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JS | I 've been broadening my horizons learning javascript and I have a quick question about style . I used to use a literal notation when making my code like this.but I would have problems accessing certain variables within the object , it would claim a few did n't exist nomatter what . So I started using this , cause it w... | var foo = { bar : function ( ) { /*something*/ } } ; var foo = { } ; foo.bar = function ( ) { /*something*/ } ; | Good Javascript code |
JS | I 've created a simple JavaScript application using AngularJS.I 'm using npm and Bower to manage my dependencies , Gulp to automatise my tasks and I want to use the CommonJS ' module.exports/require ( ) to tie everything up together : I decided to go for Browserify to bundle this all up . There 's my very empty and cle... | `` browser '' : { `` angular '' : `` ./bower_components/angular/angular.min.js '' } , '' browserify '' : { `` transform '' : [ `` browserify-shim '' ] } , '' browserify-shim '' : { `` angular '' : { `` exports '' : `` angular '' } } 'use strict ' ; var angular = require ( 'angular ' ) ; angular.module ( 'MyApp ' , [ ] ... | Browserify overrides its own configuration when browsing a folder that contains a package.json ? |
JS | In a simple HTML page , I used the following vueJs code . I need to click on the button which will insert a checkbox and a text into the DOM.My code follows : And the javascript part is : When I run the page , I find the following error message in console : [ Vue warn ] : Invalid handler for event `` click '' : got und... | < template id= '' add-item-template '' > < div class= '' input-group '' > < input v-model= '' newItem '' placeholder= '' add shopping list item '' type= '' text '' class= '' form-control '' > < span class= '' input-group-btn '' > < button @ click= '' addItem '' class= '' btn btn-default '' type= '' button '' > Add ! < ... | VueJs : use method from root element inside a component |
JS | I 've lately browsed js code and the following syntax keeps coming up : This is unfamiliar syntax to me . Is it only to define two names for the same function ? If so , why not only define it as bar.bi = function ( ) ? | var foo = bar.bi = function ( ) { ... } | Purpose of var a = b.c = function ( ) { } syntax |
JS | The problem : I have a jQuery heavy page that has a built in admin interface . The admin functions only trigger when an admin variable is set . These functions require a second library to work properly and the second file is only included if the user is an admin when the page is first created . The functions will never... | < script type= '' text/javascript '' src= '' script.js '' > < /script > < script type= '' text/javascript '' src= '' user.js '' > < /script > admin = false ; // Assume this $ ( `` .something '' ) .dblclick ( function ( ) { if ( admin ) adminstuff ( ) ; // Implemented in admin.js ( not included ) else userstuff ( ) ; } ... | A question about referencing functions in Javascript |
JS | Is it possible to use es6 constructor instructions on another instance by changing the `` this '' context ( call , apply or other ) ? This is possible using es5 `` classes '' . Here is a small example of what I mean : Edit : My question has nothing to do with the new keyword . The answer I 'm looking for is how to run ... | function ES5 ( ) { this.foo = 'foo ' ; } class ES6 { constructor ( ) { this.bar = 'bar ' ; } } var a = new ES6 ( ) ; ES5.call ( a ) ; console.log ( a.foo + a.bar ) ; //foobarvar b = new ES5 ( ) ; //Reflect.construct ( ES6 ) ; ? ? ES6.call ( b ) ; //TypeError : Class constructor ES6 can not be invoked without 'new'conso... | How to use es6 constructor instructions with a different context |
JS | I am trying to make my own custom input autocomplete API using Jquery and bootstrap 4.I want to show a preview of the list items text in the input filed whenever they are selected . I was able to do that by changing the value . However it was not what I wanted .My AutocomleteWhat I wantI want a preview of the text in t... | < ! doctype html > < html lang= '' en '' > < head > < meta charset= '' utf-8 '' > < meta name= '' viewport '' content= '' width=device-width , initial-scale=1 '' > < link rel= '' stylesheet '' href= '' https : //maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css '' > < ! -- jQuery library -- > < scrip... | How do I add a preview text to my custom built autocomplete ? |
JS | I have promise objects which need to work synchronize . For example second promise should n't work before first one is done . If first one rejects first one has to be executed again.I have implemented some examples.This one works well.call getVal , wait 2000ms , return , i++ , again call getVal ... ..But I need to cont... | getVal ( ) { return new Promise ( function ( resolve , reject ) { setTimeout ( function ( ) { resolve ( 19 ) } , 2000 ) ; } ) ; } async promiseController ( ) { for ( var i =0 ; i < 5 ; i++ ) { var _val = await this.getVal ( ) console.log ( _val+'prom ' ) ; } } getVal ( ) { return new Promise ( function ( resolve , reje... | How To Synchronise Promise Objects ? |
JS | I 'm not sure if there is a simple way of doing this , but is there a way to find multiple instances in an unknown string ? For example : Without knowing the value of the above string , can I return something that will tell me that there are 3 instances of `` hello '' and 3 instances of `` bye '' ( I 'm not worried abo... | hellohellohellobyebyebyehello | Algorithm ( or regular expression ) needed to find multiple instances of anything |
JS | I made a simple web UI with JSFiddle and I am wondering if the same UI can be made without using JavaScript.A Fiddle says more than 1000 words.So the question is ( because it seems unclear for some people ) : How can I achieve the same results without using any JavaScript ? PS : I do n't want to use JavaScript to re-ca... | < div class= '' A '' > < div class= '' B '' > B < /div > < div class= '' C '' > This stays fixed when scrolling horizontally , but scrolls along when scrolling down the parent . < /div > < /div > .A { background-color : yellow ; height : 400px ; width : 700px ; overflow : scroll ; position : relative ; } .B { backgroun... | Is this possible without using javascript ? |
JS | I 'm having trouble understanding javaScript promises . I wrote the following code : I immediately see this in my Chrome developer console : But after I wait 5 seconds , the message automatically changes to black like this image : I 've never seen this behaviour before between my javaScript code and a developer console... | var p = new Promise ( function ( resolve , reject ) { reject ( Error ( `` hello world '' ) ) ; } ) ; setTimeout ( ( ) = > p.catch ( e= > console.log ( e ) ) ,5000 ) ; var p = new Promise ( function ( resolve , reject ) { resolve ( `` hello world '' ) ; } ) ; setTimeout ( ( ) = > p.then ( e= > console.log ( e ) ) ,5000 ... | With a Promise , why do browsers return a reject twice but not a resolve twice ? |
JS | This is driving me nuts ! I have got an axios call returning an json array object in console - Check ! Now I need to do 2 things with this result : when fully expanded this response is large - and there are thousands of them . Rather than store 1000s of giant json reponses in a vuex state - I want to first only extract... | > ( 100 ) [ { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … } , { … ... | How can I extract specific values from all items in axios response object to a a vuex state |
JS | let 's say I have this code in javascript : and let the code in the servlet be : Will xhr1 still wait for new changes in readystate ? Or it is closed as soon as it gets the first response ? If it remains open , will it lead to memory leaks/slower browser after a while and accumulating a few of those ? Should I always c... | function doAnAjaxCall ( ) { var xhr1 = new XMLHttpRequest ( ) ; xhr1.open ( 'GET ' , '/mylink ' , true ) ; xhr1.onreadystatechange = function ( ) { if ( this.readyState == 4 & & this.status==200 ) { alert ( `` Hey ! I got a response ! `` ) ; } } ; xhr1.send ( null ) ; } public class RootServlet extends HttpServlet { pu... | What is the life span of an ajax call ? |
JS | So I really prefer using unobtrusive javascript to inline javascript . I find it much easier to work with.The problem that I keep running into , is that I do n't know how to get data for each specific element that I want to work with.For example : I have a list , and I generate the following HTML ( this is pseudo-code ... | < % for e in list % > < a href= '' # '' class= '' delete '' > < % =e % > < /a > < ! -- < % = e.id % > ? ? -- > < % end % > $ ( ' a.delete ' ) .click ( function ( ) { // Ajax request using `` e.id '' } ) ; | Ajax requests with unobtrusive javascript over lists of elements |
JS | colorbox v1.3.15 from colorpowered.com has this javascript in it 's minified code : this seems to run perfectly , should it ? | c.name=i+ +new Date ; | javascript odd syntax : c.name=i+ +new Date ; |
JS | First of all , you can find an example of my code in JS Fiddle and also below the question.I 'm working on a personal training webapp and basically you can hit play and then you get five minutes to do a series of tasks in a random order . The program creates the sessionTasks array in which are put in a random order tas... | mainMenu ( ) ; var totalSessionTasks , taskIterator , selectedTimeInSecs = 300 ; var taskTimer = new Timer ( `` # taskTimer '' , nextTask ) ; var globalTimer = new Timer ( `` # globalTimer '' , function ( ) { } ) ; var tasks = [ [ `` First task '' , 0 , 30 ] , [ `` Second task '' , 0 , 15 ] , [ `` Third task '' , 0 , 1... | Timer function not working correctly when stopped and started multiple times |
JS | I 'm trying to get a handle on web workers when I came across a very peculior behaviour . For some reason it 's terminated after a few seconds , even though I have code in it that 's running.Here 's my code ; Main JavaScript-file : Worker file : As stated , the worker just stops functioning after a few seconds , 10-20s... | $ ( document ) .ready ( function ( ) { var worker = new Worker ( `` js/TestWorker.js '' ) ; worker.addEventListener ( 'message ' , function ( event ) { console.log ( event.data ) ; } ) ; worker.addEventListener ( 'error ' , function ( event ) { console.log ( event ) ; } ) ; } ) ; ( function ( ) { var updateCounter = 0 ... | Why is my Web Worker terminated ? |
JS | ObjectiveOnce the maximum number of players ( two goalies , six defensemen , twelve forwards ) in each of their categories have been chosen , the remaining players picked with the class is-inactive should been set to cursor : defaultClarification of the problemAll the players have the class is-inactive as a default , a... | .player { display : inline-block ; margin-top : 15px ; margin-right : 20px ; vertical-align : top ; cursor : pointer ; position : relative ; } < div class= '' player player -- goalie year -- 1990 '' > < div class= '' tooltip tooltip -- tall '' > < p class= '' tooltip__name '' > Brian Elder < /p > < p class= '' tooltip_... | Setting cursor to default for elements with is-inactive class |
JS | Before I get yelled at for trying something so reckless , let me tell you that I would n't do this in real life and it 's an academic question.Suppose I 'm writing a library and I want my object to be able to make up methods as they are needed.For example if you wanted to call a .slice ( ) method , and I did n't have o... | window.onerror = function ( e ) { var method = / ' ( . * ) ' $ /.exec ( e ) [ 1 ] ; console.log ( method ) ; // slice return Array.prototype [ method ] .call ( this , arguments ) ; // not even almost gon na work } ; var myLib = function ( a , b , c ) { if ( this == window ) return new myLib ( a , b , c ) ; this [ 1 ] =... | Resume from an error |
JS | I 'm working on a little jQuery widget to add to my portfolio/knowledge base . The widget works , and cycles through 5 slides , however , it does not loop back around to slide 1 as it should . It only advances to a blank slide , and the page requires refreshing to move back or forward again . I am a Javascript/jQuery b... | // ( document ) .ready ( ) ; makes sure that all elements on the page are //loaded before loading the script $ ( document ) .ready ( function ( ) { //alert ( 'Doc is loaded ' ) ; //specifies speed to change from image to image , in ms var speed = 500 ; //specifies auto slider option var autoswitch = true ; //Autoslider... | jQuery slider not going to beginning |
JS | I 'm using a node.js server , the Spotify API , and the spotify-web-api-js node module to create a web application where the user can enter an artist 's name , see a list of songs from related artists , and then optionally save that playlist to their own Spotify account . However , i 'm still having trouble with the la... | if ( params.access_token ) { s.setAccessToken ( params.access_token ) ; s.getMe ( ) .then ( function ( data ) { console.log ( data ) ; console.log ( data.id ) ; user_id = data.id ; async.times ( counter , function ( n , next ) { s.getArtistTopTracks ( relatedArtists [ n ] .id , `` US '' , function ( err , data2 ) { rel... | How to pick an event listener that will let me wait until async.times is finished to run a function |
JS | Does going from to really speed things up ? I am thinking it does because php can fetch and embed a file 's contents faster than the client 's browser can make a full request for the file , because php is n't going over the network . Is the main difference that the traditional method can be cached ? | < script type= '' text/javascript '' src= '' jquery.js '' > < /script > < script type= '' text/javascript '' > < ? php echo file_get_contents ( 'jquery.js ' ) ; ? > < /script > | Is this an optimization ? |
JS | Look edits below ! I am currently looking for a way to overload the toString method of one specific function that is generated dynamically ( returned by function ) . I know I can overload the toString function of Function.prototype , but this will overload all toString functions of all functions , I want to avoid this.... | var obj = { callme : function ( ) { return function ( ) { // Dynamically fetch correct string from translations map return `` call me , maybe '' ; } } } // Binding callme to func , allowing easier accessvar func = obj.callme.bind ( obj ) ; console.log ( func , func ( ) ) func.toString = function ( ) { return this ( ) ;... | Overwrite toString for specific function |
JS | I 'm checking the number of digits in a string using the match and length properties . Here is the codepen with my function http : //codepen.io/PiotrBerebecki/pen/redMLEInitially when returning numberOfDigits.length I was getting an error message ( Can not read property 'length ' of null ) . I 've solved this issue by ... | function checkLength ( str ) { let numberOfDigits = str.match ( /\d/g ) ; return ( numberOfDigits & & numberOfDigits.length ) ; } console.log ( checkLength ( 'T3xt w1th sOme numb3rs ' ) ) ; console.log ( checkLength ( 'Text with some numbers ' ) ) ; | Why I 'm not getting an error when checking the length of null |
JS | Is there a faster way of writing this ? I 'm thinking of something like : | if ( $ ( ' # id ' ) .val ( ) ==7 || $ ( ' # id ' ) .val ( ) ==8 || $ ( ' # id ' ) .val ( ) ==9 ) { console.log ( 'value of # id is 7 , 8 , or 9 ! ' ) } ; if ( $ ( ' # id ' ) .val ( ) == 7||8||9 ) { console.log ( 'value of # id is 7 , 8 , or 9 ! ' ) } ; | Is there a faster way of writing OR operator ? |
JS | I have recently added a HasValue function to our internal javascript library : A during a convorsation with a coworker , we came up with the idea of also adding another function that would basically just be the inverse : perhaps HasNoValue , or IsNothingIf we ended up doing that we would have : However , we 're not sur... | function HasValue ( item ) { return ( item ! == undefined & & item ! == null ) ; } function HasNoValue ( item ) { return ( item === undefined || item === null ) ; } function HasValue ( item ) { return ! HasNoValue ( item ) ; } if ( HasValue ( x ) & & ! HasValue ( y ) ) if ( HasValue ( x ) & & HasNoValue ( y ) ) | Is it worth the effort to have a function that returns the inverse of another function ? |
JS | I have simple code here.The intention of it is to verify the user with the user who wrote the post and allow the verified user to edit the post.The console says : Which means they are equal in value and also equal in types.I tried with == too , but that also does n't work.I am suspecting there needs to be something don... | exports.edit = function ( req , res ) { Post.findById ( req.params.post_id , function ( err , post ) { if ( err ) { return res.json ( { type : false , message : '' error ! '' } ) ; } else if ( ! post ) { return res.json ( { type : false , message : '' no post with the id '' } ) } else { console.log ( req.user._id , typ... | why does Javascript comparison not work with objects ? |
JS | I thought this was an easy task but it is getting really complex . See the Code.It is throwing error , can not read split of undefined . How to fix this ? | // Convert `` rgb ( 255 , 255 , 255 ) '' to ( 255 , 255 , 255 ) and then to Hex code var data = { color : '' rgb ( 165,199,72 ) '' , color : '' rgb ( 229,121,74 ) '' , color : '' rgb ( 105,177,222 ) '' } // rgb To Hex Conversion var componentToHex = function ( c ) { var hex = c.toString ( 16 ) ; return hex.length == 1 ... | Substring , Split , String to Number and RGB to HEX |
JS | I have a npm package of React components which are using flow for type-checking.It would be useful for the users of my components to have access to my flow types . However at the moment I am compiling my code using Babel which strips all type information.My project structure is as follows : For example one of my types ... | ||- flowdecls myTypes.js| -components - Component1 Component1.js| - lib - Component1.js ( compiled using Babel ) - Component1.js.flow ( created using flow-copy-source ) declare type DataItemIconType = { iconElement : React $ Element < React $ ElementType > , color ? : string , hoverColor ? : string } iconList : Array <... | Exporting my own Flow type with npm package ? |
JS | I think I understand prototypical inheritance in JS but am having trouble writing code to demonstrate a particular idea I have . Consider this extremely simple scenario , where Manager objects derive from Employee objects : The output is : Oddly enough , it seems to me that we 've succeeded in demonstrating prototypica... | function Employee ( ) { this.name = `` Axel '' ; this.dept = `` R & D '' ; } function Manager ( ) { Employee.call ( this ) ; this.reports = [ `` Report 1 '' , `` Report 2 '' , `` Report 3 '' ] ; } console.log ( new Manager ( ) ) ; Manager { name : `` Axel '' , dept : `` R & D '' , reports : Array [ 3 ] } | Prototypical inheritance without prototype ? |
JS | I have a timer in Javascript that fires once per second to update some text in the page ( HTML5 ) like this : This works fine except that if this code runs while the user is dragging a scrollbar handle the drag is aborted . This is a very annoying user interface behavior which I have not been able to resolve . If I com... | document.getElementById ( 'CountDown ' ) .innerHTML = `` some string '' ; | Setting HTM5 text kills scrollbar drag in Chrome |
JS | I wrote a simple input field with a button in it . Code is as given below . As you can see , when I click in input field , button disappears . When I click outside that form , it reappears . But I do n't want it to disappear when clicked on input field . How can I do that ? | form { width : 50 % ; } /* Style the search field */.add-on { position : relative ; } .add-on input { width : 100 % ; border-radius : 0 ; } .add-on button { position : absolute ; border-radius : 0 ; top : 2px ; right : 3px ; height : 33px ; width : 60px ; z-index : 2 ; font-size : 14px ; padding : 5px ; } < link href= ... | Disappearing button in HTML |
JS | What 's the best way to find out whether a variable is a string or not ( and , likewise , a number , a boolean , etc . ) ? Usually you will find : But people forget that one can also create string objects directly using var foo = new String ( `` bar '' ) ; - whether that is a good idea or not is an entirely different m... | function isString ( value ) { return typeof value === 'string ' ; } // option 1function isString ( value ) { return ( typeof value === 'string ' ) || /^function String\ ( \ ) /.test ( value.constructor + `` ) ; } // option 2function isString ( value ) { return ( typeof value === 'string ' ) || ( value.constructor === S... | Checking the type of a variable |
JS | I am trying to make a timer which indirectly syncs with the video . When starttimer is clicked , it should starts my timer and tickle each second.Here is the process : But my timer , is not functioning properly . It works fine , when I start the timer but when I forward by n seconds , it sometimes goes by n and sometim... | 1 . Start the video2 . At a certain time in video , click to start the timer3 . Timer starts from 00:00:00 and should tickle each second.4 . If the video is forwarded by ` n ` seconds timer should be 'timer+n ` seconds . Same for the case , when video is rewinded - ` timer-n ' var mtimer = 0 ; $ ( ' # starttimer ' ) .c... | How to make the timer tickle each second and make it jump when video is forwarded or rewinded ? |
JS | I would like to provide Gamepad support for my Vue app . I would like to listen to the events from the Gamepad API.I do n't want to attach those listeners to a component because I have to deal with them globally . So where should I attach those listeners ? Should I add each event to the App.vue component , because it '... | export default { on_browser_gamepadconnected : ( { commit } , e ) = > { // do something } , } ; | listening to browser events from the Vuex store |
JS | What is the purpose of using // in the following code . If old browsers doesnt support javascript then the symbols < ! -- -- > will ignore js code . In case browsers support JS , these symbols < ! -- -- > will be ignored . Then wats the use of // symbols . | < html > < body > < script type= '' text/javascript '' > < ! -- document.getElementById ( `` demo '' ) .innerHTML=Date ( ) ; // -- > < /script > < /body > < /html > | Commenting in JavaScript |
JS | Take a look at the following code : As I execute this code , the following result is displayed : As Node.js documentation explains , the setImmediate is executed after I/O callbacks , but in this example setImmediate is being executed before I/O callbacks , am I missing something ? | var fs = require ( 'fs ' ) ; var pos = 0 ; fs.stat ( __filename , function ( ) { console.log ( ++pos + `` FIRST STAT '' ) ; } ) ; fs.stat ( __filename , function ( ) { console.log ( ++pos + `` LAST STAT '' ) ; } ) ; setImmediate ( function ( ) { console.log ( ++pos + `` IMMEDIATE '' ) } ) | Node.js setImmediate executed before I/O callbacks ( Event Loop ) |
JS | Have problem with submiting information via ajax.Have for example 20 rows . Click on row and it opens all information about services.Here html : Then its div with infoI 'm saving class in localStorage . And then user edits value in field and hes out off that field , I update that information with ajaxThe problem is tha... | $ ( 'tr ' ) .click ( function ( ) { var servicesUpdateId = $ ( this ) .attr ( 'data ' ) ; $ ( `` # '' +servicesUpdateId ) .css ( { `` display '' : '' block '' , 'opacity ' : ' 0 ' } ) .animate ( { left : ' 0 ' , opacity : ' 1 ' , } ) ; // save form class for ajax submit localStorage.setItem ( `` formId '' , servicesUpd... | Ajax issue with input , textarea blur |
JS | I have this code of Javascript that i got from a forum for my html page : My question is how can i make it reload when the time is up . so if seconds and minuets = 0 , it would reload.Or if you have a better simple times , please show me how : ) | < html > < head > < title > Countdown < /title > < script type= '' text/javascript '' > // set minutesvar mins = 0.1 ; // calculate the seconds ( do n't change this ! unless time progresses at a different speed for you ... ) var secs = mins * 60 ; function countdown ( ) { setTimeout ( 'Decrement ( ) ',1000 ) ; } functi... | How to make javascript timer reload |
JS | I can not figure out the best way to dynamically generate a multidimensional array with 2 different sizes.We have a UI that requires a row of 4 items , then 3 . This pattern would repeat until the content in the array has been spent.This is essentially what I need to do : This is what I currently have , it is only conv... | // Convertconst array = [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ] ; // toconst rows [ [ 1 , 2 , 3 , 4 ] , [ 5 , 6 , 7 ] , [ 8 , 9 , 10 , 11 ] , [ 12 , 13 , 14 ] ] ; const buildRows = ( arr , length ) = > arr.reduce ( ( rows , val , i ) = > ( i % length == 0 ? rows.push ( [ val ] ) : rows [ rows.len... | Javascript Generate Multidimensional array of 2 sizes |
JS | From React DOCS : https : //reactjs.org/docs/state-and-lifecycle.htmlState Updates May Be AsynchronousReact may batch multiple setState ( ) calls into a single update for performance.This makes total sense . If you have something like the function below , it would be very inefficient to re-render on every setState call... | const [ state1 , setState1 ] = useState ( false ) ; const [ state2 , setState2 ] = useState ( false ) ; const [ state3 , setState3 ] = useState ( false ) ; function handleClick ( ) { setState1 ( true ) ; setState2 ( true ) ; setState3 ( true ) ; } function App ( ) { console.log ( `` App rendering ... '' ) ; const [ cou... | When does React re-render after a setState call made inside an event handler |
JS | I just found that if I use new Date ( '2015-1-1 ' ) , the time is no timezone effect , but If I use new Date ( '2015-01-01 ' ) the time has timezone effect in Node.js.I output 4 Date ( ) : the output is you can see the last time is 08:00:00 because I 'm in +8 timezone.I think the output depends on the digit of the mont... | console.log ( new Date ( '2015-1-1 ' ) ) ; console.log ( new Date ( '2015-01-1 ' ) ) ; console.log ( new Date ( '2015-1-01 ' ) ) ; console.log ( new Date ( '2015-01-01 ' ) ) ; Thu Jan 01 2015 00:00:00 GMT+0800 ( CST ) Thu Jan 01 2015 00:00:00 GMT+0800 ( CST ) Thu Jan 01 2015 00:00:00 GMT+0800 ( CST ) Thu Jan 01 2015 08... | Date ( '2015-1-1 ' ) outputs different from Date ( 2015-01-01 ) |
JS | Here is the fiddle : http : //jsfiddle.net/7txt3/29/I want to have the record needle on the record like you see in my image below rotate on to the record when the user clicks the play button ( see the fiddle ) The needle placement is not necessarily final and I might want it to be in the top right corner . ( I 've incl... | $ ( function ( ) { var station = $ ( '.player-station ' ) , record = $ ( '.record2 : first ' ) , playBtns = $ ( '.play ' ) , info = $ ( '.nprecinfo ' ) ; var isPlaying = false ; playBtns.click ( function ( ) { var btn = $ ( this ) ; if ( btn.text ( ) == 'STOP ' ) { btn.text ( 'PLAY ' ) ; record.css ( { '-webkit-animati... | Need help to add/modify to my script to include some rotation using jquery and css |
JS | I have a live ( ) function in my jquery below : Now some people say that the live ( ) function is slowing fading away and that is better to use the on ( ) function . If this is true then how do I change the code above to on ( ) function rather than a live ( ) function ? Is it important I do n't use live ( ) or does it ... | $ ( `` # qandatbl td.weight input '' ) .live ( `` change '' , calculateTotal ) ; function calculateTotal ( ) { var totalweight = hundred ; $ ( `` # qandatbl td.weight input '' ) .each ( function ( i , elm ) { totalweight = totalweight - parseInt ( $ ( elm ) .val ( ) , 10 ) ; } ) ; $ ( `` # total-weight '' ) .text ( tot... | How to change my code from a .live ( ) to .on ( ) |
JS | I execute the following javascript code in iOS using JavaScriptCore framework . The javascript code is browserified . printFunc is a method implemented in Swift that just prints something to console . Here is the implementation : The problem is that I am receiving the following error : Even more strange is that if I re... | var myCallback = undefined ; *browserify logic* { 1 : [ function ( require , module , exports ) { var q = require ( './user ' ) ; var p = new Promise ( function ( resolved , reject ) { myCallback = function ( ) { resolved ( 'test ' ) ; } } ) ; p.then ( function ( x ) { printFunc ( 'test ' ) ; } ) .catch ( function ( e ... | 'Error compiling builtin ' while executing JavaScript code in JavaScriptCore |
JS | Every time I create some class , I need to do the same boring procedure : Is there any way to make it more elegant and shorter ? I use Babel , so some ES7 experimental features are allowed . Maybe decorators can help ? | class Something { constructor ( param1 , param2 , param3 , ... ) { this.param1 = param1 ; this.param2 = param2 ; this.param3 = param3 ; ... } } | A shorter class initialisation in ECMAScript 6 |
JS | I have a wizard form with four steps which is for ordering Parts , the first step user provide details ( Stock Type and Approver who will approve the order ) which are validated correctly . Second step user will select which parts to order from the table . On the table , a user is allowed to enter quantity which is les... | `` use strict '' ; function scroll_to_class ( element_class , removed_height ) { var scroll_to = $ ( element_class ) .offset ( ) .top - removed_height ; if ( $ ( window ) .scrollTop ( ) ! = scroll_to ) { $ ( '.form-wizard ' ) .stop ( ) .animate ( { scrollTop : scroll_to } , 0 ) ; } } function bar_progress ( progress_li... | Moving line items from one table to another table and validating data entered on the first table before adding selected line items to second table |
JS | I want to draw a line on screen from the top of the page to the bottom when the user scrolls the page and have an arrow at the bottom of it . I do n't want to use fixed position so that its always in the same spot , I want it to indicate where they are on the page by determining the page length etc . I have the followi... | //Draw dotted line on scroll - works to certain extent but scrolls off page $ ( window ) .scroll ( function ( ) { if ( $ .windowScrollTop ( ) > 10 ) { var pos = $ .windowScrollTop ( ) ; var scrollHeight = $ ( window ) .innerHeight ( ) ; var element = $ ( ' # dashes ' ) ; $ ( ' # line ' ) .css ( 'height ' , pos - scroll... | calculate positioning of image to follow scroller |
JS | I 've successfully ssh 'd into Google Cloud Compute via CLI with a command like the following : But using the ssh2 module is n't giving any output , including errors.I 'm tailing /var/log/secure as I 'm debugging the node script and I can see log entries when I ssh in and close the session from CLI , but nothing at all... | ssh -i ~/.ssh/my-ssh-key me @ ipnumber var fs = require ( 'fs ' ) ; var Client = require ( 'ssh2 ' ) .Client ; var connSettings = { host : IP , // 'XXX.XXX.XXX.XX ' port : PORT , // XXXX username : ME , privateKey : privateKey , //fs.readFileSync ( location , 'utf8 ' ) passphrase : passphrase , password : password } ; ... | ssh2 module fails silently with creds that succeed from CLI |
JS | Can you explain me why does the second call of fn gives an error ? The code is below.Here 's a JSfiddle that reproduces the error http : //jsfiddle.net/KjkQ2/ | function Test ( n ) { this.test = n ; var bob = function ( n ) { this.test = n ; } ; this.fn = function ( n ) { bob ( n ) ; console.log ( this.test ) ; } ; } var test = new Test ( 5 ) ; test.fn ( 1 ) ; // returns 5test.fn ( 2 ) ; // returns TypeError : 'undefined ' is not a function | Javascript 'this ' |
JS | I have a script which allows to replace undesired HTML tags and escape quotes to `` improve '' security and prevent mainly script tag and onload injection , etc ... . This script is used to `` texturize '' content retrieved from innerHTML.However , it multiples near by 3 my execution time ( in a loop ) . I would like t... | function safe_content ( text ) { text = text.replace ( / < script [ ^ > ] * > . * ? < \/script > /gi , `` ) ; text = text.replace ( / ( < p [ ^ > ] * > | < \/p > ) /g , `` ) ; text = text.replace ( /'/g , ' & # 8217 ; ' ) .replace ( / & # 039 ; /g , ' & # 8217 ; ' ) .replace ( / [ \u2019 ] /g , ' & # 8217 ; ' ) ; text ... | Javascript - Regex/replace optimization |
JS | I want communicate between java and typescript with encrypted AES-GCM data ( PBKDF2 hash used for password ) .I used random bytes for pbkdf2 : This is my java PBKDF2 Code : and this is typescript code : Result in java and typescript : Why i have difference result ? What part of code has wrong ? UPDATEInteresting , I tr... | randomBytes ( Base64 ) : wqzowTahVBaxuxcN8vKAEUBEo0wOfcg4e6u4M9tPDFk= private String salt = `` 1234 '' ; private static final String KEY_ALGORITHM = `` AES '' ; private Key generateKey ( byte [ ] randomBytes ) throws Exception { var randomPassword = new String ( randomBytes ) ; KeySpec keySpec = new PBEKeySpec ( random... | Java and typescript generate difference PBKDF2 hash |
JS | I am not able to populate my form with data that I have received from a method called getbyId ( ) from a service , in my console I see that errors : can not read truckId of undefined , Every solution i have found is saying my form is rendered faster than the object that i want to get with a getById ( ) method and the s... | getTruckById ( id : number ) : Observable < Truck > { const url = ` $ { this.baseUrl } / $ { id } ` ; return this.http.get ( url , { headers : this.headers } ) .pipe ( map ( this.extractData ) , tap ( data = > console.log ( JSON.stringify ( data ) ) ) , catchError ( this.handleError ) ) ; } export class EditTruckCompon... | Can not read value of undefined , when components share data ? |
JS | JSFiddle exampleI 've noticed that when updating positions of svg elements in a d3-force diagram , updating the positions of elements using ( in the case of circles ) the cx and cy attributes is much smoother than using the transform attribute.In the example JSFiddle , there are two separate force simulations side-by-s... | sim_transform.on ( 'tick ' , function ( ) { circles_transform.attr ( 'transform ' , function ( d ) { return 'translate ( ' + d.x + ' , ' + d.y + ' ) ' ; } ) ; } ) ; sim_position.on ( 'tick ' , function ( ) { circles_position .attr ( 'cx ' , function ( d ) { return d.x ; } ) .attr ( 'cy ' , function ( d ) { return d.y ;... | Force simulation is jittery when using svg transforms to update position |
JS | I noticed something weird with timezones and Javascript Date object.Trying this on a Linux box : I found it impossible to get an object that represents the 21th of october 2012 . Every attemps to get a Date between 00:00 and 01:00 that day results in a date the day before between 11:00 PM and 00:00 . ( Windows user may... | $ TZ='America/Sao_Paulo ' js js > new Date ( 2012 , 9 , 21 , 0 , 0 , 0 ) .toString ( ) `` Sat Oct 20 2012 23:00:00 GMT-0300 ( BRST ) '' | Is there a way to represent the 21 october 2012 in a Javascript ` Date ` object ? |
JS | In JavaScript , the NaN value can be represented by a wide range of 64-bit doubles internally . Specifically , any double with the following bitwise representation : Is interpreted as a NaN . My question is : suppose I cast two 32-bit uints to a JS Number using ArrayBuffers , pass it around , then cast it back to two 3... | x111 1111 1111 xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx | Are JS engines allowed to change the bits of a NaN ? |
JS | There is such a construction : When you click on one item , all are toggled together . How to fix it ? | $ ( 'ul li ' ) .click ( function ( ) { $ ( '.hide ' ) .slideToggle ( 300 ) ; $ ( this ) .toggleClass ( `` hide-open '' ) ; } ) ; < script src= '' https : //cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js '' > < /script > < ul > < li > Пункт < div class= '' hide '' > Это скрыто < /div > < /li > < li > Пункт < ... | How to show an element only in this block ? |
JS | I 'd like to add different child elements to my nodes depending on the node type . Therefore the node has an attribute called type . All nodes should consist of a g element with the dependent child elements.I tried this by using D3s filter functionality but i 'm stuck as my code does n't add the child elements only onc... | self.domNodes = this.svg.append ( ' g ' ) .attr ( 'class ' , 'nodes ' ) .selectAll ( '.node ' ) function draw ( ) { self.domNodes = self.domNodes.data ( self.nodes , ( node ) = > node.id ) self.domNodes.exit ( ) .remove ( ) // all nodes self.domNodes.enter ( ) .append ( ' g ' ) .attr ( 'class ' , ( node ) = > ` node $ ... | Adding child elements to specific nodes in a force-directed graph using d3js |
JS | Rails version : 5.2.2Chrome version : 78.0.3904.87While testing my website on Chrome today , I noticed that it scrolls to the top of the page whenever I submit an AJAX request . This behavior is undesirable and does not happen on other browsers , such as Firefox . I 've tried debugging the issue but could n't figure ou... | < div id= '' container '' > < % = form_for ( obj , method : : post , url : url , remote : true ) do |f| % > < button id= '' obj- < % = obj.id % > -btn '' type= '' button '' class= '' btn btn-primary obj-btn '' title= '' Add '' data-toggle= '' tooltip '' data-placement= '' left '' > Add < /button > < % end % > < /div > ... | Chrome scrolling to the top of the page after a remote form request |
JS | I 'm trying to grasp how the functions in Donut3D.js - > http : //plnkr.co/edit/g5kgAPCHMlFWKjljUc3j ? p=preview handle the inserted data : Above all , where is it set that the data 's startAngle is set at 0 degrees ? I want to change it to 45º , then to 135º , 225º and 315º ( look at the image above ) .I 've located t... | Donut3D.draw = function ( id , data , x /*center x*/ , y/*center y*/ , rx/*radius x*/ , ry/*radius y*/ , h/*height*/ , ir/*inner radius*/ ) { var _data = d3.layout.pie ( ) .sort ( null ) .value ( function ( d ) { return d.value ; } ) ( data ) ; var slices = d3.select ( `` # '' +id ) .append ( `` g '' ) .attr ( `` trans... | How is data parsed in this 3D piechart ? |
JS | I am building a jQuery plugin to manage form collections . The plugin aims to add add , remove , move up and move down buttons to alter that collection . A collection 's root node always contains a selector , such as .collection.A button can be anything as soon as it has the .add classI implemented min and max options ... | < div class= '' collection '' > < div > something < /div > < div > something < /div > < div > < div class= '' add '' > + < /div > < /div > < div > something < /div > < div class= '' collection '' > < div > something < /div > < div > something < /div > < div > < div class= '' add '' > + < /div > < /div > < div > somethi... | How to find elements that are not deeper than a selector ? |
JS | I am able to change design of the title attribute inside anchor tag , even though the default one is coming along with changed one.I 'm wondering if it 's possible to remove default title tooltip as shown below ? Here 's my code so far : Thanks in advance . | < a title= '' Edit '' > < img alt= '' '' src= '' dist/img/edit.png '' > < /a > a : hover { color : red ; position : relative ; } a [ title ] : hover : after { content : attr ( title ) ; padding : 2px 4px ; color : # 333 ; position : absolute ; left : 0 ; top : 100 % ; white-space : nowrap ; z-index : 20px ; -moz-border... | Remove the old design title of an anchor tag after applying CSS on it |
JS | There is an open-source application which visually displays a difference between two BPMN diagrams.I want to see what the application looks like when it runs.How can I start it under Ubuntu ? I tried to run node app.js in the directory bpmn-js-diffing/app but got the errorI looked at the Gruntfile in search of a `` run... | module.js:341 throw err ; ^Error : Can not find module 'jquery ' at Function.Module._resolveFilename ( module.js:339:15 ) at Function.Module._load ( module.js:290:25 ) at Module.require ( module.js:367:17 ) at require ( internal/module.js:16:19 ) at bpmn-js-diffing/app/app.js:6:11 at Object. < anonymous > ( bpmn-js-dif... | How can I start this Node.JS application ? |
JS | The issue I 'm seeing is that when you load Stripe Checkout into a page using their canonical `` Custom '' guide , configure it , and then open and close it a few times , the browser memory usage continually jumps . It sometimes , sorta gets released a little , but the residual always grows . And on a long lived page/S... | performance.memory.usedJSHeapSize | Is Stripe Checkout leaking memory ? |
JS | I 'm a new developer at my company and I do mostly front-end web development . Our team is frequently asked by our Sales and Marketing people to incorporate 3rd party javascripts on our site . `` Here 's a 'little code snippet ' . Our vendor asked if you could put this in our home page '' This makes me very nervous . I... | < script src= '' http : //www.mycompany.com/js/vendor-file.js '' type= '' text/javascript '' > < script src= '' http : //www.vendor.com/js/file.js '' type= '' text/javascript '' > var a = document.createElement ( `` script '' ) ; a.type = `` text/javascript '' ... etc . | What are the risks associated with Hosting 3rd party Javascripts ? |
JS | In JavaScript when you define an array using the literal syntax , array elements may be omitted by using additional commas : I noticed that when accessing the values that the omitted values were not `` own properties '' In contrast , if you define an array explicitly setting undefined , it will be set as an `` own prop... | a = [ 1 , 2 , 3 ] ; // 1 , 2 , 3b = [ 1 , , 2 , 3 ] ; // 1 , undefined , 2 , 3 b.hasOwnProperty ( 1 ) ; //false c = [ 1 , undefined , 2 , 3 ] ; c.hasOwnProperty ( 1 ) ; //true | Do elided array elements ever produce an own property ? |
JS | I often need to map a list of functions ( processors ) to several arrays ( channels ) of float data ) so I have written a helper function ... This reads OK ( to me at least ! ) but mapping an array of functions over another array seems like such a generic thing I ca n't help but wonder if it IS `` a thing '' already i.... | const mapMany = function ( processors , channels ) { processors.forEach ( function ( processor ) { channels = channels.map ( ( channel ) = > channel.map ( processor ) ) ; } ) ; return channels ; } ; | Mapping an array of functions over an array in Javascript |
JS | Suppose there are many < select > elements in a form . I need a selector that selects a < select > element whose selected option has certain text . To explain , let 's say there are 5 < select > elements of class `` color '' . Each of them have 3 < option > with texts `` white '' , `` black '' , `` green '' . Now I nee... | < select class= '' color '' > < option value= '' '' > < /option > < option value= '' 1 '' > white < /option > < option value= '' 2 '' > black < /option > < option value= '' 2 '' > green < /option > < /select > | How to select a < select > element on the basis of selected option text ? |
JS | I currently have a Web Application that runs off a global Javascript-based API , and it is initialized like this : This API is shared across many `` Widgets '' that live in the Web Application , and they should all run off this single Api instance so they can pass data to each other.AJAX is currently used to load these... | var Api = { someVar : `` test '' , someFunction : function ( ) { return `` foo '' ; } } Api.myExtension = { myNewFunction : function ( ) { return `` bar '' ; } } Api.foo = { test : `` bar '' } // allowedApi.someVar = `` changing the existing someVar '' ; // not allowed var Api = { Debug : { Messages = new Array , Write... | Protecting a Global Javascript `` API '' Object |
JS | Self explanatory fiddle : http : //jsfiddle.net/5FG2n/1/Say I have a view with two controllers , one containing the other . The outer controller is static , but I need to set the inner controller based on a scope variable from the outer . The scope variable will be the inner controller 's name as a string ( eg . 'Inner... | < div ng-app='app ' ng-controller='OuterCtrl ' > < div ng-controller='dynamicCtrl ' > { { result } } < /div > < /div > angular.module ( 'app ' , [ ] ) .controller ( 'OuterCtrl ' , [ ' $ scope ' , function ( $ scope ) { // Instead of hard coding the controller here , // how do I resolve the string 'InnerCtrl ' to the //... | How do I resolve and assign an inner controller from the outer 's scope ? |
JS | Take a look at the following code : Why is it that when it 's a variable , the code works correctly yet when it is a number literal , it fails ? And also , strangely enough , why does the following line work ? In the above line , I basically enclosed the literal in parenthesis . | Number.prototype.isIn = function ( ) { for ( var i = 0 , j = arguments.length ; i < j ; ++i ) { if ( parseInt ( this , 10 ) === arguments [ i ] ) { return true ; } } return false ; } ; var x = 2 ; console.log ( x.isIn ( 1,2,3,4,5 ) ) ; // < = 'true'console.log ( 2.isIn ( 1,2,3,4,5 ) ) ; // < = Error : 'missing ) after ... | Strange syntax of Number methods in JavaScript |
JS | Is this possible or am I barking up the wrong tree here ? Update : The object which fnc is supposed to represent is actually a Sarissa dom document . Here is a more elaborate version of fnc ( ) , dom_doc ( ) . The accepted answer below has been integrated into the function below.Demo : JSFIDDLE | var data = 'one ' ; function fnc ( ) { this.out = function ( ) { return data ; } } var instance = new fnc ( ) ; alert ( instance.out ) ; data = 'two ' ; alert ( instance.out ) ; // I know that this would achieve that , but that 's not what I would like to know.alert ( instance.out ( ) ) ; data = 'two ' ; alert ( instan... | Is it possible to make a JavasScript function act as if it was a string , no ( ) |
JS | I 've decided to learn node , an so I 'm following , to begin with , The Node Beginner Book . As in I guess a lot of other resources , there is the `` simple HTTP server '' , first step , something like : As I understand it , when someone , in this case me though localhost:8888 , makes a request , an event is triggered... | var http = require ( `` http '' ) ; http.createServer ( function ( request , response ) { response.writeHead ( 200 , { `` Content-Type '' : `` text/plain '' } ) ; response.write ( `` Hello World '' ) ; response.end ( ) ; } ) .listen ( 8888 ) ; | Where does `` request '' and `` response '' come from , and how could I have found out ? |
JS | I am looking for a way to trigger different methods for the buttons in typeahead suggestions.I am using backbone underneath and I have created the related events and methods that are to be called , however when I click only the default typeahead : selected event happens , but not the methods I have created.EDITThis is ... | var QueryInputView = Backbone.View.extend ( { el : $ ( ' # query-input ' ) , initialize : function ( options ) { _.bindAll ( this , 'clearInput ' , 'initWordSuggester ' , 'initConceptSuggester ' , 'initTypeAhead ' ) ; this.initTypeAhead ( ) ; } , events : { 'keyup ' : function ( e ) { if ( e.keyCode === 13 ) { var valu... | Include buttons inside typeahead suggestions using Backbone |
JS | I 'm trying to use AWS SimpleDB Javascript SDK.Here 's the web page with my script : When I run this web page I get this error : XMLHttpRequest can not load https : //sdb.amazonaws.com/ . No 'Access-Control-Allow-Origin ' header is present on the requested resource . Origin 'null ' is therefore not allowed access . The... | < ! doctype html > < html > < head > < meta charset= '' utf-8 '' > < title > < /title > < /head > < body > < script src= '' https : //dl.dropboxusercontent.com/u/4111969/aws-sdk-2.1.39.js '' > < /script > < script type= '' text/javascript '' > AWS.config.update ( { accessKeyId : 'MYKEY ' , secretAccessKey : 'MYSECRET '... | Errors with AWS SimpleDB Javascript SDK |
JS | I am fetching images from JSON with help of this codepen1 : https : //codepen.io/kidsdial/pen/QomgvaNow along with images , i need to fetch the text , so i tried codepen2 : https : //codepen.io/kidsdial/pen/bZvRgR , but text is not displaying ... .Text `` Good Food Good life `` should display like below image : Please ... | var target ; let jsonData = { `` layers '' : [ { `` x '' : 0 , `` layers '' : [ { `` x '' : 0 , `` src '' : `` Y1rcR8A.jpg '' , `` y '' : 0 } , { `` x '' : 476 , `` src '' : `` 0x7hnlG.png '' , `` y '' : 326 } , { `` justification '' : `` center '' , `` x '' : 357 , `` y '' : 633 , `` src '' : `` 2ccd95bae3f2a0c8249205... | Get the Text values from json file |
JS | I spent some time debugging a strange infinite loop problem in a NodeJS testsuite . It only happens under rare conditions but I can reproduce it when I attach to the chrome debugger.I think it has to do with V8 's handling of stack traces in exceptions and a extension that the vows library did to the AssertionError obj... | $ git clone https : //github.com/flatiron/vows.git $ cd vows & & npm install & & npm install should $ cat > example.jsvar should = require ( 'should ' ) ; var error = require ( './lib/assert/error.js ' ) ; try { ' x'.should.be.json ; } catch ( e ) { console.log ( e.toString ( ) ) ; } // without debug , it should fail a... | V8 lazy generation of stack traces seems to cause an infinite loop in the vows library |
JS | I am using the latest version of redux-observable and Rxjs i.eThe store - middleware , setup looks like this : And my epic looks like thisSo when I executed the program for the first time I got the following error : I googled it and found a solution here which says to install rxjs-compat @ 6 ( however it does n't makes... | // My version '' redux-observable '' : `` ^1.0.0 '' , '' rxjs '' : `` ^6.3.2 '' // Setting up middlewaresimport { pingEpic } from './epics ' ; import pingReducer from './reducers/pingReducer ' ; import { combineReducers , createStore , applyMiddleware } from 'redux ' ; import { combineEpics , createEpicMiddleware } fro... | rxjs v6 / redux-observable v1.0.0 : Operators not working in epic |
JS | I 'm developing a Javascript based multiplayer game.So far I have the basic server , client and networking ready.I did have an issue where my player was moving faster on a 120Hz screen as opposed to a 60Hz screen . I 've fixed this by multiplying the player 's movementspeed by the deltatime of the 'requestAnimationFram... | //Game loop ; Do each 1/60th of a secondsetInterval ( gameTick , 1000/60 ) ; function gameTick ( ) { player.handleKeys ( ) ; enemies.foreach ( ( enemy ) = > { enemy.update ( ) ; } ) ; } //Draw loop ; match to player screen refresh ratewindow.requestAnimationFrame ( gameLoop ) ; function gameLoop ( ) { player.draw ( ) ;... | Javascript multiplayer game - requestAnimationFrame for game/physics logic ? |
JS | I am not sure how the Javascript engines ( specifically browser engines ) store an array.For example - how much memory would this use ? I want to map integer dates as array indexes , but I need to be sure it is n't a bad idea . | var x = new Array ( 0 , 1 , 2 , 1000 , 100000000 ) ; | Javascript Array index fundamentals |
JS | Can someone explain to me why the resulting promise ( d ) from the code below is resolved immediately ? I 'm creating an array of promises that are pending forever , so the resulting promise should also be pending forever as it waits for all subsequent promises to finish ( as presented here ) . I 've been using promise... | //promises that are never resolved nor rejectedvar a = new Promise ( function ( r , re ) { } ) ; var b = new Promise ( function ( r , re ) { } ) ; var c = new Promise ( function ( r , re ) { } ) ; var d = [ a , b , c ] .reduce ( function ( previousPromise , promise ) { return previousPromise.then ( promise ) ; } , Prom... | Why this chain of promises immediately resolves ? |
JS | When sorting an array of numbers in JavaScript , I accidentally used < instead of the usual - -- but it still works . I wonder why ? Example : And an example array for which this does not work ( thanks for Nicolas 's example ) : | var a = [ 1,3,2,4 ] a.sort ( function ( n1 , n2 ) { return n1 < n2 } ) // result is correct : [ 4,3,2,1 ] [ 1,2,1,2,1,2,1,2,1,2,1,2 ] | Why does sorting a JS array of numbers with < work ? |
JS | Here is one of the questions in JavaScript online-test before job interview : Q : How to make comparison a == b to be true ? ( e.g . console.log ( a == b ) // true ) I answered that it 's impossible because a and b are two different instances of F and equal comparison in JS in case of non-primitives compares reference.... | function F ( ) { } ; var a = new F ( ) ; var b = new F ( ) ; | How to make comparison of objects ` a == b ` to be true ? |
JS | I am trying to use jQuery to select a div , but ignore all divs selected that are children of a selected div . No divs have any other way to identify them other than an HREF that I am matching . For example : This code selects all the divs , including the child . How can I limit it to only select the outermost div that... | outerdiv = $ ( ' a [ href^= '' http : //bizmate . `` ] ' ) .closest ( 'div ' ) ; outerdiv.prepend ( `` This was selected '' ) < script src= '' https : //ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js '' > < /script > < div > Wo n't be selected < div > Powered by < a href= '' http : //bizmate.in '' > Bizmate <... | jquery select outermost div of a nest of selected divs |
JS | I have two arrays.I want a percent value that describes how much their values are different.I try using MSE and RMSE : and : The result is : I do n't think that this result is correct.First of all , mse and rmse are not in range [ 0 , 100 ] , and then are values very large even if the two array are not so different.Wha... | /*** Mean Squared Error* MSE = ( 1/n ) * Ʃ [ ( r - p ) ^2 ] } */export function computeMse ( a , b ) { const size = a.length let error = 0 for ( let i = 0 ; i < size ; i++ ) { error += Math.pow ( b [ i ] - a [ i ] , 2 ) } return ( 1 / size ) * error } /*** Root Mean Squared Error* RMSE = √MSE*/export function computeRm... | How to find a precent value that represents how much two arrays are different ? |
JS | I have created a simple jQuery & CSS based tooltip which is not aligned horizontally even though i made positioning relative for the parent anchor link element.If i set the width of the tooltip to 100px or something else it works but the content may extend so I want to avoid defining the width.HTML CodejQuery CodeCSS C... | < div class= '' single-session-speakers '' > < div class= '' single_session_speaker_thumb iva_tip '' > < a href= '' # '' > < img alt= '' Anne-Marie '' src= '' http : //placehold.it/50x50 '' > < span class= '' ttip '' > Anne-Marie < /span > < /a > < /div > < div class= '' single_session_speaker_thumb iva_tip '' > < a hr... | jQuery tooltip not horizontally aligned ? |
JS | Trying to make a method which can read the current visible text inside of a element . The method you see below is as far as i 've gotten the past few days.Is there anything more reliable for getting the visible text in a element other than using a caret/range ? Cause the issue I 'm having is that i have a lot of overfl... | function getTextInColumn ( rect ) { var startX = rect.left ; var startY = rect.top ; var endX = rect.left + rect.width - 2 ; var endY = rect.top + rect.height - 2 ; var start , end , range = null ; var i = 0 ; var rangeText = `` ; while ( ( rangeText === `` & & i < 100 & & endY > 5 ) ) { range = null ; if ( typeof docu... | Get visible text in CSS3 columns |
JS | I 'm running into an issue where a callback sent to setTimeout from a resolved promise never get executed . supposed I have the following : myFunc ( ) never resolves as it is continually waiting for callbackCalled to be true.What am I missing here ? I believe the event loop should n't be blocked since I 'm calling awai... | class Foo { constructor ( foo ) { this.foo = foo ; } async execUntilStop ( callback ) { const timeoutLoopCallback = ( ) = > { if ( this.stopExec ) return ; callback ( { data : 'data ' } ) ; setTimeout ( timeoutLoopCallback , 10 ) ; } ; setTimeout ( timeoutLoopCallback , 10 ) ; return { data : 'data ' } ; } stop ( ) { t... | timeout loop in promise never executes after promise is resolved ? |
JS | There is already an answer posted to the test itself , which can be found here , but I ca n't seem to figure out why that answer is correct.The part of the test that is giving me trouble is : The ( apparently ) correct answer , as noted in the above linked question is I tried inserting the answer - fixed the syntax err... | var keys = [ ] ; var fruits = [ 'apple ' , 'orange ' ] ; for ( propertyName in fruits ) { keys.push ( propertyName ) ; } ok ( keys.equalTo ( [ '__ ' , '__ ' , '__ ' ] ) , 'what are the properties of the array ? ' ) ; ok ( keys.equalTo ( [ ' 0 ' , ' 1 ' , 'fruits.prototype ' ) , 'what are the properties of the array ? '... | Having trouble understanding a reflection test in Javascript Koans |
JS | I 've been playing around with Elm for a couple of days and I wanted to make a port of Moment.JS , since I 've seen a lack of libraries for what I wanted , and Moment just has everything that I need.The thing is that I always face the same error . I have Moment.JS in my Native folder ( it is named MomentJS.js ) and ano... | var _user $ project $ Native_Moment = ( function ( ) { var moment = require ( 'moment ' ) ; var format = function ( format , date ) { return moment ( ) .format ( ) ; } return { format : format } ; } ) ( ) ; module Moment exposing ( format ) { -| A module desc @ docs format- } import Native.MomentJSimport Native.Moment ... | Making a Native ELM module with Moment.js |
JS | Save the following HTML as a local file . Something like /tmp/foo.html , then open that in Firefox ( I 'm on 49.0.2 ) I do n't have a server running on port 1234 , so the requests do n't even successfully connect.The behavior I 'd expect here is for all the requests to fail , and be done with it.What actually happens i... | < ! DOCTYPE html > < html > < head > < meta charset= '' utf-8 '' > < /head > < body > < script src= '' http : //localhost:1234/a.js '' > < /script > < script src= '' http : //localhost:1234/b.js '' > < /script > < script src= '' http : //localhost:1234/c.js '' > < /script > < script src= '' http : //localhost:1234/d.js... | Why do browsers re-request scripts on non-200 response ? |
JS | I 've installed Django-CMS onto an existing site and while it is n't throwing errors , it is n't working . In particular , the header on a given page appears when I use `` / ? edit '' but none of the pull down menus work , and very little ( possibly none ) of the JavaScript works . Other facets : I 've done this on a l... | DEBUG = TrueTEMPLATE_DEBUG = FalseALLOWED_HOSTS = [ '*domain of server* ' ] LOGIN_REDIRECT_URL = '/'DATABASES = { 'default ' : { 'ENGINE ' : 'django.db.backends.mysql ' , 'NAME ' : '*db name* ' , 'USER ' : '*username* ' , 'PASSWORD ' : '*password* ' , 'HOST ' : `` , 'PORT ' : `` , } } STATIC_ROOT = '*path to the static... | Django-cms installs , but pull-downs and other JS does n't work - ideas for fixing ? |
JS | I prototyped Function so that it has a getBody function : See here for more info.I tried to test it this way : but received an error : TypeError : console.log.getBody is undefined.I figured out that maybe this happens because console.log was defined before I actually prototyped Function so I created an empty function x... | Function.prototype.getBody = function ( ) { // Get content between first { and last } var m = this.toString ( ) .match ( /\ { ( [ \s\S ] * ) \ } /m ) [ 1 ] ; // Strip comments return m.replace ( /^\s*\/\/ . * $ /mg , '' ) ; } ; console.log ( console.log.getBody.getBody ( ) ) ; console.log ( x.getBody.getBody ( ) ) ; | Why does prototyping Function not affect console.log ? |
JS | I have a div card that plays an animation on click , which includes the card scaling to be larger . The problem is that as the card scales bigger , it 's edges are displayed under other cards . http : //puu.sh/oqtEs/5c0d525f8d.pngI was able to fix this by adding z-index to the class that gets applied on click , but it ... | @ -webkit-keyframes flipAndZoomAnim { 0 % { -webkit-transform : rotateY ( 0deg ) scale ( 0.5 ) translateZ ( 1px ) } 20 % { -webkit-transform : rotateY ( 180deg ) scale ( 0.5 ) translateZ ( 1px ) } 40 % { -webkit-transform : rotateY ( 180deg ) scale ( 1.0 ) translateZ ( 1px ) } 80 % { -webkit-transform : rotateY ( 180de... | Display div affected by CSS3 animation on top |
JS | I was considering ways to create arrays containing a default value using native methods and ended up withExpecting it to be 2 or 3 times slower than a while loop , as the native methods have to loop twice whereas while loops only once , so I compared it on jsperf againstand it is actually 18 to 27 times slower ( tested... | function pushMap ( length , fill ) { var a = [ ] , b = [ ] ; a.length = length ; b.push.apply ( b , a ) ; return b.map ( function ( ) { return fill ; } ) ; } function whileLengthNew ( len , val ) { var rv = new Array ( len ) ; while ( -- len > = 0 ) { rv [ len ] = val ; } return rv ; } | Why is filling a new Array so much faster with a while loop ? |
JS | I made this ( run snippet below ) I just need to add one feature to be able to use it on the site I 'm building it for . Some of the floating shards need to be blurred to give a sense of depth . Can Canvas do this , and if so , how ? | var Canvas = document.getElementById ( ' c ' ) ; var ctx = Canvas.getContext ( '2d ' ) ; var resize = function ( ) { Canvas.width = Canvas.clientWidth ; Canvas.height = Canvas.clientHeight ; } ; window.addEventListener ( 'resize ' , resize ) ; resize ( ) ; var elements = [ ] ; var presets = { } ; presets.shard = functi... | HTML Canvas , blurring drawn polygon |
JS | I ca n't seem to putting the width and height of an img into another class css . If you could just give me a hint that would be nice ! Here 's my code : Of course its wrapped around a document.ready . Here is the HTML where i want to take the width and height of the image : And here is the div class where i want to giv... | $ ( '.Main_hover ' ) .each ( function ( ) { var $ this = $ ( this ) ; var w = $ this.find ( 'img ' ) .width ( ) ; var h = $ this.find ( 'img ' ) .height ( ) ; $ ( `` .fusion-button-wrapper '' ) .css ( 'height ' , h ) ; $ ( `` .fusion-button-wrapper '' ) .css ( 'width ' , w ) ; } ) ; < div class= '' imageframe-align-cen... | Javascript get width and height of img and place it into css of another class |
JS | I have two buttons that are using the same ng-click with different params.No matter what I do , the buttons pass the same param as what is in the first function call.With a simple controller function for testing , the same param gets logged . In this case , it is true for both.These seems to happen only in Ionic , not ... | < label class= '' item item-input '' > < button ng-click= '' takePicture ( true ) '' > Save Settings < /button > < button ng-click= '' takePicture ( false ) '' > Choose from Gallery < /button > < /label > $ scope.takePicture = function ( my_param ) { console.log ( my_param ) ; } | Function parameter the same in button ng-click |
JS | for some reason I do that every time because I find it clean . I declare variables on top to use them below . I do that even if I use them only once.Here is an example ( using jQuery framework ) : I tend to do that in PHP too . Am I right if I believe it 's not very memory efficient to do that ? Edit : Thank you for al... | $ ( `` # tbListing '' ) .delegate ( `` a.btnEdit '' , `` click '' , function ( e ) { var storeId = $ ( this ) .closest ( `` tr '' ) .attr ( `` id '' ) .replace ( `` store- '' , `` '' ) , storeName = $ ( this ) .closest ( `` tr '' ) .find ( `` td : eq ( 1 ) '' ) .html ( ) , $ currentRow = $ ( this ) .closest ( `` tr '' ... | Is that a bad Javascript practice I 'm doing here ? |
JS | I have an array which contains `` Zeros '' and I want to move all ofthe `` Zeros '' to the last indexes of the array.The expected output is : But instead I get : | [ 1,2,3,0,0,0,0 ] [ 1,2,0,3,0,0,0 ] let a = [ 0 , 1 , 2 , 0 , 0 , 3 , 0 ] ; let count = 0 ; let len = a.length ; for ( i = 0 ; i < len ; i++ ) { if ( a [ i ] == 0 ) { count = count + 1 ; a.splice ( i , 1 ) ; } } for ( j = 0 ; j < count ; j++ ) { a.push ( 0 ) ; } console.log ( a ) ; | Weird bug in Javascript splice method |
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