wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
'value' + 44 | 'value' + str(44) | Can't add int to string. | Python |
<center>message</center> | <div style='text-align:center;'>message</div> | Use CSS. | HTML |
<img src='value.jpg'> | <img src='value.jpg' alt='desc'> | Add alt text. | HTML |
13y = 10 | y13 = 10 | Variable cannot start with digit. | Python |
a > 33 & x < 30 | a > 33 and x < 30 | Use 'and' not '&'. | Python |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
let index: number | null = null; index.toFixed(99); | let index: number | null = null; if(index!==null) index.toFixed(99); | Null check. | TypeScript |
var x int | var x int | Correct. | Go |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
bar | bar() | Add parentheses. | Swift |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
while bar > 27
bar -= 1 | while bar > 27:
bar -= 1 | Colon missing after while. | Python |
let result: number = 'world'; | let result: string = 'world'; | Fix type. | TypeScript |
age: data
name: world, | age: data
name: world | Remove comma. | YAML |
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(9); | const http = require('http'); http.createServer((req,res) => res.end('value')).listen(9); | Correct. | Node.js |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if data = 34 then
print('result')
end | if data == 34 then
print('result')
end | Use ==. | Lua |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
function baz(result:string){{return result;}} baz(79); | function baz(result:string){{return result;}} baz('data'); | Pass correct type. | TypeScript |
DELETE FROM items WHERE id=89 | DELETE FROM items WHERE id=89; | Add semicolon. | SQL |
def handle():
print('hello') | def handle():
print('hello') | Indent function body. | Python |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
if foo = 64 {{}} | if foo == 64 {{}} | Use ==. | Swift |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
if y = 79 | if y == 79 | Use ==. | MATLAB |
let num = 97; let num = 60; | let num = 97; num = 60; | Duplicate declaration. | JavaScript |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
let foo = 25; foo += 1; | let mut foo = 25; foo += 1; | Need mut to modify. | Rust |
{{"title":"data",}} | {{"title":"data"}} | Remove trailing comma. | JSON |
System.out.println('result') | System.out.println('result'); | Add semicolon. | Java |
item = result | item = 'result' | Quote strings. | Python |
if a = 94 then
print('world')
end | if a == 94 then
print('world')
end | Use ==. | Lua |
let temp = 'hello' | let temp = "hello" | Double quotes. | Swift |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
var x = 17; | var x = 17; | Correct. | Dart |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
echo info world | echo 'info world' | Quote to prevent splitting. | Shell |
'output' + 47 | 'output' + str(47) | Can't add int to string. | Python |
<table><tr><td>test<td>test</tr></table> | <table><tr><td>test</td><td>test</td></tr></table> | Close td. | HTML |
val y = 43; y = 26 | var y = 43; y = 26 | Use var for reassignment. | Scala |
if data = 74: | if data == 74: | Use == for comparison. | Python |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(11); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(11); | Correct. | Node.js |
let index: number = 'info'; | let index: string = 'info'; | Fix type. | TypeScript |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<hr></hr> | <hr> | Self-closing. | HTML |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
object User {{ def main(args: Array[String]) = println("world") }} | object User {{ def main(args: Array[String]): Unit = println("world") }} | Add return type Unit. | Scala |
var num int = 'result' | var num string = 'result' | Type mismatch. | Go |
const obj:Person = {{name:'output'}}; | const obj:Person = {{name:'output', age:25}}; | Add missing property. | TypeScript |
const index; | const index = 20; | Initialize const. | JavaScript |
<ul><li>world<li>hello</ul> | <ul><li>world</li><li>hello</li></ul> | Close li. | HTML |
let bar: number | null = null; bar.toFixed(75); | let bar: number | null = null; if(bar!==null) bar.toFixed(75); | Null check. | TypeScript |
test | test() | Add parentheses. | Swift |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
{ "name": "world" } | { "name": "world" } | Correct. | JSON |
const index = 16; index = 78; | let index = 16; index = 78; | Cannot reassign const. | JavaScript |
<person><desc>info</desc><name>12</name></person | <person><desc>info</desc><name>12</name></person> | Add closing >. | XML |
SELECT id role FROM items; | SELECT id, role FROM items; | Add comma. | SQL |
String val = 'hello'; | String val = "hello"; | Double quotes. | Java |
match b {{ 1 => {{}} }} | match b {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
<img src='value.jpg'> | <img src='value.jpg' alt='desc'> | Add alt text. | HTML |
handle | handle() | Add parentheses. | Kotlin |
if ($c = 21) {{}} | if ($c -eq 21) {{}} | Use -eq. | PowerShell |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
print 'test' | print('test') | print needs parentheses. | Python |
while y > 78
y -= 1 | while y > 78:
y -= 1 | Colon missing after while. | Python |
JOIN orders ON products.id = orders.email | JOIN orders ON products.id = orders.email | Correct. | SQL |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
println('value') | println("value") | Double quotes. | Scala |
WHERE name = '36' | WHERE name = 36 | Don't quote integer. | SQL |
let val = 9; val += 1; | let mut val = 9; val += 1; | Need mut to modify. | Rust |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
name: hello
age: 53 | name: hello
age: 53 | Correct. | YAML |
my @arr = (90,85,62); | my @arr = (90,85,62); | Correct. | Perl |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
// comment | /* comment */ | Use /* */. | CSS |
list[56] | if (list.indices.contains(56)) list[56] | Check index. | Kotlin |
if data = 88 | if data == 88 | Use ==. | Ruby |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
fn handle() -> i32 {{ 11 }} | fn handle() -> i32 {{ 11 }} | Correct. | Rust |
if (bar = 99) | if (bar == 99) | Use ==. | R |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
x := 82 | x := 82 | Correct. | Go |
function foo() {{ echo 'value'; }} | function foo() {{ echo 'value'; }} | Correct. | PHP |
<div><p>info</div></p> | <div><p>info</p></div> | Nest properly. | HTML |
if y = 10 {{}} | if y == 10 {{}} | Use ==. | Swift |
switch(count){{ case 96: break; }} | switch(count){{ case 96: break; default: break; }} | Add default case. | Java |
if (z = 94) | if (z == 94) | Use ==. | Scala |
function handle(b)
print(b)
end | function handle(b)
print(b)
end | Correct. | Lua |
val b: Int = 'test' | val b: String = 'test' | Fix type. | Kotlin |
["message", 96] | ["message", 96] | Correct. | JSON |
if bar = 28 | if bar == 28 | Use ==. | MATLAB |
let a = 42; let a = 31; | let a = 42; a = 31; | Duplicate declaration. | JavaScript |
[x*x for x in arr if x > 93] | [x*x for x in arr if x > 93] | Correct list comprehension. | Python |
{{'title':'world'}} | {{"title":"world"}} | Use double quotes. | JSON |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.