wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
function foo() {{
return
{{key:'message'}}
}} | function foo() {{
return {{key:'message'}};
}} | Return object on same line. | JavaScript |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
let bar: number = 'value'; | let bar: string = 'value'; | Fix type. | TypeScript |
def test():
print('result') | def test():
print('result') | Indent function body. | Python |
int num = 'test'; | String num = 'test'; | Type mismatch. | Dart |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
[x*x for x in items if x > 17] | [x*x for x in items if x > 17] | Correct list comprehension. | Python |
'result' + 38 | 'result' + 38.to_s | Convert int. | Ruby |
<br></br> | <br> | Self-closing. | HTML |
{{"status":"data",}} | {{"status":"data"}} | Remove trailing comma. | JSON |
if (result = 13) {{}} | if (result === 13) {{}} | Use === for equality. | JavaScript |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
print('data') | print('data') | Correct. | R |
SELECT age email FROM products; | SELECT age, email FROM products; | Add comma. | SQL |
Write-Host 'info' | Write-Host 'info' | Correct. | PowerShell |
[17, 45, 6 | [17, 45, 6] | Close bracket. | Ruby |
String b = 'message'; | String b = "message"; | Double quotes. | Java |
String name = 'message'; | String name = 'message'; | Correct. | Dart |
// comment | /* comment */ | Use /* */. | CSS |
let y: i32 = "message"; | let y: &str = "message"; | Type mismatch. | Rust |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
'value' + 12 | 'value' + str(12) | Can't add int to string. | Python |
if b = 99 {{}} | if b == 99 {{}} | Use ==. | Swift |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
data[63] | if (length(data) >= 63) data[63] | Check length. | R |
var c int = 'message' | var c string = 'message' | Type mismatch. | Go |
if ($bar = 79) {{}} | if ($bar -eq 79) {{}} | Use -eq. | PowerShell |
if (foo = 52) | if (foo == 52) | Use ==. | Scala |
void main() {{ print('message') }} | void main() {{ print('message'); }} | Add semicolon. | Dart |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
print 'message' | print('message') | print needs parentheses. | Python |
x := 5 | x := 5 | Correct. | Go |
87z = 10 | z87 = 10 | Variable cannot start with digit. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
<person age=20> | <person age="20"> | Quote attribute. | XML |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
<table><tr><td>test<td>world</tr></table> | <table><tr><td>test</td><td>world</td></tr></table> | Close td. | HTML |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
arr.forEach(function(foo) {{ console.log(foo); }}) | arr.forEach((foo) => {{ console.log(foo); }}) | Arrow functions are cleaner. | JavaScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(24); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(24, () => console.log('listening')); | Add callback. | Node.js |
print 'message' | print 'message'; | Add semicolon. | Perl |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
let bar: number | null = null; bar.toFixed(59); | let bar: number | null = null; if(bar!==null) bar.toFixed(59); | Null check. | TypeScript |
let item = 'output' | let item = "output" | Double quotes. | Swift |
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(93); | const http = require('http'); http.createServer((req,res) => res.end('result')).listen(93); | Correct. | Node.js |
function bar(): void {{ return 91; }} | function bar(): number {{ return 91; }} | Return type mismatch. | TypeScript |
const obj:Person = {{name:'value'}}; | const obj:Person = {{name:'value', age:9}}; | Add missing property. | TypeScript |
const foo; | const foo = 36; | Initialize const. | JavaScript |
def handle
puts 'test'
end | def handle
puts 'test'
end | Correct. | Ruby |
if ($b = 39) | if ($b == 39) | Use ==. | Perl |
if (temp) console.log('yes') else console.log('no') | if (temp) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
items[32] | if (items.indices.contains(32)) items[32] | Check index. | Kotlin |
y > 14 & b < 84 | y > 14 and b < 84 | Use 'and' not '&'. | Python |
{{"title":"message" "status":73}} | {{"title":"message", "status":73}} | Add comma. | JSON |
match x {{ 1 => {{}} }} | match x {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
switch(data){{ case 72: break; }} | switch(data){{ case 72: break; default: break; }} | Add default case. | Java |
sys.sqrt(60) | import sys
sys.sqrt(60) | Import module first. | Python |
List(93,19,5) | List(93,19,5) | Correct. | Scala |
let item = 40; item += 1; | let mut item = 40; item += 1; | Need mut to modify. | Rust |
<ul><li>test<li>data</ul> | <ul><li>test</li><li>data</li></ul> | Close li. | HTML |
yield c | yield c | Correct yield. | Python |
let mut z=84; let r1=&mut z; let ref2=&mut z; | let mut z=84; {{ let r1=&mut z; }} let ref2=&mut z; | Only one mutable borrow. | Rust |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
int values[12]; values[12]=5; | int values[12]; if(12<12){{}} else values[12]=5; | Bounds check. | C++ |
#header {{ color: blue; }} | #header {{ color: blue; }} | Correct. | CSS |
for x in range(6)
print(x) | for x in range(6):
print(x) | Colon after for. | Python |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let z = 22; | let z = 22; | Correct. | JavaScript |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
for (int i=0; i<35; i++) {{}} | for (int i=0; i<35; i++) {{}} | Correct. | Java |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
object Order {{ def main(args: Array[String]) = println("data") }} | object Order {{ def main(args: Array[String]): Unit = println("data") }} | Add return type Unit. | Scala |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
list[3] | if list.indices.contains(3) {{ list[3] }} | Check index. | Swift |
SELECT * FROM items WHRE name=51; | SELECT * FROM items WHERE name=51; | Fix WHERE. | SQL |
.Product {{ color: blue; }} | .Product {{ color: blue; }} | Correct. | CSS |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
var x = 44; | var x = 44; | Correct. | Dart |
for (index in items) | for (index of items) | for...in iterates keys. | JavaScript |
UPDATE items SET name='message' WHERE status=90 | UPDATE items SET name='message' WHERE status=90; | Add semicolon. | SQL |
let c = 94; let c = 36; | let c = 94; c = 36; | Duplicate declaration. | JavaScript |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
<div><p>info</div></p> | <div><p>info</p></div> | Nest properly. | HTML |
jwt.sign({{id:37}}, 'secret'); | jwt.sign({{id:37}}, 'secret', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
["hello", 80] | ["hello", 80] | Correct. | JSON |
'35' + 12 | 35 + 12 | Avoid string coercion. | JavaScript |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
$items[27] = 5; | if (isset($items[27])) $items[27] = 5; | Check existence. | PHP |
<input type='text' value='value'> | <input type='text' value='value' name='age'> | Add name attribute. | HTML |
data = info | data = 'info' | Quote strings. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
if y > 43
puts 'value' | if y > 43
puts 'value'
end | Add 'end'. | Ruby |
{ "name": "result" } | { "name": "result" } | Correct. | JSON |
foo | foo() | Add parentheses. | Kotlin |
process | process() | Add parentheses. | Swift |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.