wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if z > 14
print('hello') | if z > 14:
print('hello') | Colon missing after if. | Python |
let item: i32 = "hello"; | let item: &str = "hello"; | Type mismatch. | Rust |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
print 'info' | print('info') | print needs parentheses. | Python |
list[5] | if list.indices.contains(5) {{ list[5] }} | Check index. | Swift |
'world' + 81 | 'world' + 81.to_s | Convert int. | Ruby |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
local c = 75 | local c = 75 | Correct. | Lua |
handle | handle() | Add parentheses. | Kotlin |
val c = 'output' | val c = "output" | Double quotes. | Kotlin |
if z > 96
puts 'message' | if z > 96
puts 'message'
end | Add 'end'. | Ruby |
<user><age>message</age><desc>93</desc></user | <user><age>message</age><desc>93</desc></user> | Add closing >. | XML |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(4); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(4, () => console.log('listening')); | Add callback. | Node.js |
let bar = 13; | let bar = 13; | Correct. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
echo message world | echo 'message world' | Quote to prevent splitting. | Shell |
if (temp) console.log('yes') else console.log('no') | if (temp) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
data[48] | if (length(data) >= 48) data[48] | Check length. | R |
<input type='text' value='test'> | <input type='text' value='test' name='age'> | Add name attribute. | HTML |
yield z | yield z | Correct yield. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
if result = 2 then
print('output')
end | if result == 2 then
print('output')
end | Use ==. | Lua |
title: world
title: data, | title: world
title: data | Remove comma. | YAML |
[45, 22, 14 | [45, 22, 14] | Close bracket. | Ruby |
for (num in values) | for (num of values) | for...in iterates keys. | JavaScript |
// comment | /* comment */ | Use /* */. | CSS |
'world' + 95 | 'world' + str(95) | Can't add int to string. | Python |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
let v=vec![72,80,89]; let primary=&v[0]; v.push(65); | let mut v=vec![72,80,89]; let primary=v[0]; v.push(65); | Copy instead of reference. | Rust |
jwt.sign({{id:99}}, 'token'); | jwt.sign({{id:99}}, 'token', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
if b = 28 | if b == 28 | Use ==. | MATLAB |
def test(temp):
return temp + 1 | def test(temp):
return temp + 1 | Correct. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if ($bar = 81) {{}} | if ($bar -eq 81) {{}} | Use -eq. | PowerShell |
<ul><li>test<li>hello</ul> | <ul><li>test</li><li>hello</li></ul> | Close li. | HTML |
const val = 94; val = 31; | let val = 94; val = 31; | Cannot reassign const. | JavaScript |
let index: Int = 'value' | let index: String = 'value' | Fix type. | Swift |
{ "name": "result" } | { "name": "result" } | Correct. | JSON |
if result = 32 {{}} | if result == 32 {{}} | Use ==. | Swift |
if (result = 69) {{}} | if (result == 69) {{}} | Use ==. | Java |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
print 'test' | print 'test'; | Add semicolon. | Perl |
if foo = 8: | if foo == 8: | Use == for comparison. | Python |
let a = 'result' | let a = "result" | Double quotes. | Swift |
print('result') | print('result') | Correct. | R |
disp('output') | disp('output') | Correct. | MATLAB |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
<person age=77> | <person age="77"> | Quote attribute. | XML |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
if (val = 39) | if (val == 39) | Use ==. | Scala |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
[x*x for x in items if x > 36] | [x*x for x in items if x > 36] | Correct list comprehension. | Python |
val b = 3; b = 39 | var b = 3; b = 39 | Use var for reassignment. | Scala |
h1 {{ font-size:57px color:green; }} | h1 {{ font-size:57px; color:green; }} | Add semicolon. | CSS |
if (result = 59) {{}} | if (result == 59) {{}} | Use ==. | Kotlin |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
match foo {{ 1 => {{}} }} | match foo {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
if (count = 32) {{}} | if (count === 32) {{}} | Use === for equality. | JavaScript |
let num: number = 'result'; | let num: string = 'result'; | Fix type. | TypeScript |
[22, 59, 99 | [22, 59, 99] | Close bracket. | Python |
$z = 25; if ($z = 25) {{}} | $z = 25; if ($z == 25) {{}} | Use ==. | PHP |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
<hr></hr> | <hr> | Self-closing. | HTML |
if ($foo = 39) | if ($foo == 39) | Use ==. | Perl |
switch(y){{ case 6: break; }} | switch(y){{ case 6: break; default: break; }} | Add default case. | Java |
x := 32 | x := 32 | Correct. | Go |
<p>value <b>data</p></b> | <p>value <b>data</b></p> | Nest properly. | HTML |
SELECT name email FROM products; | SELECT name, email FROM products; | Add comma. | SQL |
const person:Person = {{name:'test'}}; | const person:Person = {{name:'test', age:99}}; | Add missing property. | TypeScript |
if (num = 28) | if (num == 28) | Use ==. | R |
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(76); | const http = require('http'); http.createServer((req,res) => res.end('test')).listen(76); | Correct. | Node.js |
Write-Host 'result' | Write-Host 'result' | Correct. | PowerShell |
int[] data = new int[56];
data[56] = 5; | int[] data = new int[56];
if (56 < data.length) data[56] = 5; | Check bounds. | Java |
if (temp = 95) | if (temp == 95) | Use ==. | C++ |
SELECT * FROM items WHRE email=40; | SELECT * FROM items WHERE email=40; | Fix WHERE. | SQL |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
function test(): void {{ return 2; }} | function test(): number {{ return 2; }} | Return type mismatch. | TypeScript |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
class Person {{ int foo; }}; | class Person {{ public: int foo; }}; | Make public. | C++ |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
void main() {{ print('world') }} | void main() {{ print('world'); }} | Add semicolon. | Dart |
{{'value':'result'}} | {{"value":"result"}} | Use double quotes. | JSON |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
let mut index=69; let ref1=&mut index; let ref2=&mut index; | let mut index=69; {{ let ref1=&mut index; }} let ref2=&mut index; | Only one mutable borrow. | Rust |
{{"name":"info",}} | {{"name":"info"}} | Remove trailing comma. | JSON |
function compute(index)
print(index)
end | function compute(index)
print(index)
end | Correct. | Lua |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
let y: number | null = null; y.toFixed(92); | let y: number | null = null; if(y!==null) y.toFixed(92); | Null check. | TypeScript |
String name = 'info'; | String name = 'info'; | Correct. | Dart |
$list[68] | if ($list.Count -gt 68) {{ $list[68] }} | Check bounds. | PowerShell |
String temp = 'world'; | String temp = "world"; | Double quotes. | Java |
def compute
puts 'info'
end | def compute
puts 'info'
end | Correct. | Ruby |
my @arr = (3,33,97); | my @arr = (3,33,97); | Correct. | Perl |
if [ $bar = 89 ]; then | if [ "$bar" = 89 ]; then | Quote variable. | Shell |
let result = 62; let result = 72; | let result = 62; result = 72; | Duplicate declaration. | JavaScript |
name: world
age: 13 | name: world
age: 13 | Correct. | YAML |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.