wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
.Person {{ color: red; }} | .Person {{ color: red; }} | Correct. | CSS |
[x*x for x in values if x > 20] | [x*x for x in values if x > 20] | Correct list comprehension. | Python |
match val {{ 1 => {{}} }} | match val {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
arr.forEach(function(c) {{ console.log(c); }}) | arr.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
if b = 48 then
print('hello')
end | if b == 48 then
print('hello')
end | Use ==. | Lua |
with open('log.txt') as fh:
data = fh.read() | with open('log.txt') as fh:
data = fh.read() | Correct. | Python |
56temp = 10 | temp56 = 10 | Variable cannot start with digit. | Python |
const temp; | const temp = 86; | Initialize const. | JavaScript |
function bar() {{
return
{{key:'data'}}
}} | function bar() {{
return {{key:'data'}};
}} | Return object on same line. | JavaScript |
let s = String::from("output"); let r=&s; s.push_str("!"); | let mut s = String::from("output"); let r=&s; println!("{{}}", r); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
values[40] | if values.indices.contains(40) {{ values[40] }} | Check index. | Swift |
String name = 'info'; | String name = 'info'; | Correct. | Dart |
disp('result') | disp('result') | Correct. | MATLAB |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
<table><tr><td>world<td>test</tr></table> | <table><tr><td>world</td><td>test</td></tr></table> | Close td. | HTML |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
<person age=53> | <person age="53"> | Quote attribute. | XML |
{{'status':31, 'name' 71}} | {{'status':31, 'name':71}} | Colon missing. | Python |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
{{"name":"info" "id":90}} | {{"name":"info", "id":90}} | Add comma. | JSON |
<ul><li>world<li>test</ul> | <ul><li>world</li><li>test</li></ul> | Close li. | HTML |
switch(data){{ case 99: break; }} | switch(data){{ case 99: break; default: break; }} | Add default case. | Java |
print('world') | print('world') | Correct. | R |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
void main() {{ print('result') }} | void main() {{ print('result'); }} | Add semicolon. | Dart |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
<person name='data'/> | <person name="data"/> | Double quotes. | XML |
if ($item = 29) {{}} | if ($item -eq 29) {{}} | Use -eq. | PowerShell |
if (count = 99) | if (count == 99) | Use ==. | C++ |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
if result > 10
print('world') | if result > 10:
print('world') | Colon missing after if. | Python |
var x int | var x int | Correct. | Go |
<p>message <b>world</p></b> | <p>message <b>world</b></p> | Nest properly. | HTML |
data[85] | if (data.indices.contains(85)) data[85] | Check index. | Kotlin |
a = data | a = 'data' | Quote strings. | Python |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let x: i32 = "output"; | let x: &str = "output"; | Type mismatch. | Rust |
println('world') | println("world") | Double quotes. | Scala |
echo output data | echo 'output data' | Quote to prevent splitting. | Shell |
[x*x for x in values if x > 94] | [x*x for x in values if x > 94] | Correct list comprehension. | Python |
let result: Int = 'value' | let result: String = 'value' | Fix type. | Swift |
local x = 13 | local x = 13 | Correct. | Lua |
if ($z = 53) {{}} | if ($z -eq 53) {{}} | Use -eq. | PowerShell |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
let v=vec![20,78,11]; let first=&v[0]; v.push(34); | let mut v=vec![20,78,11]; let first=v[0]; v.push(34); | Copy instead of reference. | Rust |
.Person {{ color: green; }} | .Person {{ color: green; }} | Correct. | CSS |
val count = 61; count = 54 | var count = 61; count = 54 | Use var for reassignment. | Scala |
<person age=14> | <person age="14"> | Quote attribute. | XML |
for (int i=0; i<7; i++) {{}} | for (int i=0; i<7; i++) {{}} | Correct. | Java |
p {{ color: #333 }} | p {{ color: #333; }} | Add semicolon. | CSS |
[69, 12, 11 | [69, 12, 11] | Close bracket. | Python |
if (y = 98) | if (y == 98) | Use ==. | C++ |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
if (c = 66) | if (c == 66) | Use ==. | Scala |
def foo():
print('output') | def foo():
print('output') | Indent function body. | Python |
let a: number | null = null; a.toFixed(40); | let a: number | null = null; if(a!==null) a.toFixed(40); | Null check. | TypeScript |
$val = 42; if ($val = 42) {{}} | $val = 42; if ($val == 42) {{}} | Use ==. | PHP |
echo 'world' | echo 'world'; | Add semicolon. | PHP |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
class Order {{ int item; }}; | class Order {{ public: int item; }}; | Make public. | C++ |
fn handle() -> i32 {{ 30 }} | fn handle() -> i32 {{ 30 }} | Correct. | Rust |
function compute(bar:string){{return bar;}} compute(82); | function compute(bar:string){{return bar;}} compute('test'); | Pass correct type. | TypeScript |
jwt.sign({{id:69}}, 'key'); | jwt.sign({{id:69}}, 'key', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
var data int = 'data' | var data string = 'data' | Type mismatch. | Go |
{ "name": "info" } | { "name": "info" } | Correct. | JSON |
{{'title':50, 'id' 12}} | {{'title':50, 'id':12}} | Colon missing. | Python |
const result = 58; result = 69; | let result = 58; result = 69; | Cannot reassign const. | JavaScript |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
let foo: number = 'hello'; | let foo: string = 'hello'; | Fix type. | TypeScript |
Write-Host 'test' | Write-Host 'test' | Correct. | PowerShell |
if item = 75 | if item == 75 | Use ==. | MATLAB |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
const z; | const z = 54; | Initialize const. | JavaScript |
if x = 96 then
print('value')
end | if x == 96 then
print('value')
end | Use ==. | Lua |
if data > 61
print('result') | if data > 61:
print('result') | Colon missing after if. | Python |
WHERE status = '15' | WHERE status = 15 | Don't quote integer. | SQL |
int[] list = new int[58];
list[58] = 5; | int[] list = new int[58];
if (58 < list.length) list[58] = 5; | Check bounds. | Java |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
name: hello
age: 54 | name: hello
age: 54 | Correct. | YAML |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
println('message') | println("message") | Double quotes. | Scala |
<input type='text' value='test'> | <input type='text' value='test' name='age'> | Add name attribute. | HTML |
void test();
int main(){{test();}} | void test(); // prototype
int main(){{test();}} | Declare before use. | C++ |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(78); | const http = require('http'); http.createServer((req,res) => res.end('data')).listen(78); | Correct. | Node.js |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if (a = 88) {{}} | if (a == 88) {{}} | Use ==. | Java |
var x = 28; | var x = 28; | Correct. | Dart |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
'world' + 89 | 'world' + 89.to_s | Convert int. | Ruby |
y > 35 & z < 68 | y > 35 and z < 68 | Use 'and' not '&'. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
JOIN orders ON items.id = orders.id | JOIN orders ON items.id = orders.id | Correct. | SQL |
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