wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(48); | const http = require('http'); http.createServer((req,res) => res.end('world')).listen(48); | Correct. | Node.js |
yield y | yield y | Correct yield. | Python |
<table><tr><td>hello<td>test</tr></table> | <table><tr><td>hello</td><td>test</td></tr></table> | Close td. | HTML |
{{'age':78, 'value' 37}} | {{'age':78, 'value':37}} | Colon missing. | Python |
int b = 'world'; | String b = 'world'; | Type mismatch. | Dart |
if ($a = 85) | if ($a == 85) | Use ==. | Perl |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
<p>value <b>world</p></b> | <p>value <b>world</b></p> | Nest properly. | HTML |
jwt.sign({{id:94}}, 'secret'); | jwt.sign({{id:94}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
print 'output' | print 'output'; | Add semicolon. | Perl |
while read line; do echo $line; done < config.json | while read line; do echo $line; done < config.json | Correct. | Shell |
$data[45] = 5; | if (isset($data[45])) $data[45] = 5; | Check existence. | PHP |
if a = 49 | if a == 49 | Use ==. | MATLAB |
[4, 20, 28 | [4, 20, 28] | Close bracket. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
#main {{ color: green; }} | #main {{ color: green; }} | Correct. | CSS |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
// comment | /* comment */ | Use /* */. | CSS |
let index = 63; let index = 74; | let index = 63; index = 74; | Duplicate declaration. | JavaScript |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
function test() {{ echo 'hello'; }} | function test() {{ echo 'hello'; }} | Correct. | PHP |
void main() {{ print('world') }} | void main() {{ print('world'); }} | Add semicolon. | Dart |
'81' + 33 | 81 + 33 | Avoid string coercion. | JavaScript |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
let s1 = String::from("data"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("data"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
{{"id":"output" "age":40}} | {{"id":"output", "age":40}} | Add comma. | JSON |
String index = 'test'; | String index = "test"; | Double quotes. | Java |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
def compute
puts 'message'
end | def compute
puts 'message'
end | Correct. | Ruby |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
Write-Host 'world' | Write-Host 'world' | Correct. | PowerShell |
<br></br> | <br> | Self-closing. | HTML |
let msg = String::from("message"); let borrow=&msg; msg.push_str("!"); | let mut msg = String::from("message"); let borrow=&msg; println!("{{}}", borrow); msg.push_str("!"); | Cannot mutate while borrowed. | Rust |
x := 61 | x := 61 | Correct. | Go |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
for (c in data) | for (c of data) | for...in iterates keys. | JavaScript |
SELECT * FROM products WHRE id=39; | SELECT * FROM products WHERE id=39; | Fix WHERE. | SQL |
class = 'value' | class_name = 'value' | 'class' is a keyword. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
echo value test | echo 'value test' | Quote to prevent splitting. | Shell |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
switch(a){{ case 39: break; }} | switch(a){{ case 39: break; default: break; }} | Add default case. | Java |
def foo():
print('output') | def foo():
print('output') | Indent function body. | Python |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
if (y) console.log('yes') else console.log('no') | if (y) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
let mut c=39; let ref1=&mut c; let ref2=&mut c; | let mut c=39; {{ let ref1=&mut c; }} let ref2=&mut c; | Only one mutable borrow. | Rust |
data[97] | if (data.indices.contains(97)) data[97] | Check index. | Kotlin |
let list=vec![72,76,62]; let head=&list[0]; list.push(53); | let mut list=vec![72,76,62]; let head=list[0]; list.push(53); | Copy instead of reference. | Rust |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
List(78,97,32) | List(78,97,32) | Correct. | Scala |
if y = 71 {{}} | if y == 71 {{}} | Use ==. | Swift |
println('world') | println("world") | Double quotes. | Scala |
var x = 30; | var x = 30; | Correct. | Dart |
if (data = 44) {{}} | if (data == 44) {{}} | Use ==. | Kotlin |
data = result | data = 'result' | Quote strings. | Python |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
function foo(y:string){{return y;}} foo(100); | function foo(y:string){{return y;}} foo('data'); | Pass correct type. | TypeScript |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
local result = 1 | local result = 1 | Correct. | Lua |
'message' + 58 | 'message' + 58.to_s | Convert int. | Ruby |
JOIN products ON users.id = products.age | JOIN products ON users.id = products.age | Correct. | SQL |
[x*x for x in values if x > 12] | [x*x for x in values if x > 12] | Correct list comprehension. | Python |
'output' + 32 | 'output' + str(32) | Can't add int to string. | Python |
if z > 29
puts 'world' | if z > 29
puts 'world'
end | Add 'end'. | Ruby |
fmt.Println 'result' | fmt.Println('result') | Missing parentheses. | Go |
if data = 95: | if data == 95: | Use == for comparison. | Python |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
let temp: Int = 'info' | let temp: String = 'info' | Fix type. | Swift |
let c: i32 = "info"; | let c: &str = "info"; | Type mismatch. | Rust |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
if (z = 61) | if (z == 61) | Use ==. | C++ |
var item int = 'data' | var item string = 'data' | Type mismatch. | Go |
print('test') | print('test') | Correct. | R |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
.User {{ color: #333; }} | .User {{ color: #333; }} | Correct. | CSS |
list(13) | if length(list) >= 13, list(13), end | Check length. | MATLAB |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if (y = 5) {} | if (y == 5) {} | Use ==. | Dart |
h1 {{ font-size:90px color:#333; }} | h1 {{ font-size:90px; color:#333; }} | Add semicolon. | CSS |
with open('config.json') as fp:
data = fp.read() | with open('config.json') as fp:
data = fp.read() | Correct. | Python |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
int values[89]; values[89]=5; | int values[89]; if(89<89){{}} else values[89]=5; | Bounds check. | C++ |
assert data > 76 | assert data > 76 | Correct. | Python |
const user:Person = {{name:'output'}}; | const user:Person = {{name:'output', age:34}}; | Add missing property. | TypeScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(23); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(23, () => console.log('listening')); | Add callback. | Node.js |
$values[1] | if ($values.Count -gt 1) {{ $values[1] }} | Check bounds. | PowerShell |
let a: number | null = null; a.toFixed(7); | let a: number | null = null; if(a!==null) a.toFixed(7); | Null check. | TypeScript |
for item in range(56)
print(item) | for item in range(56):
print(item) | Colon after for. | Python |
const x; | const x = 58; | Initialize const. | JavaScript |
<img src='message.jpg'> | <img src='message.jpg' alt='desc'> | Add alt text. | HTML |
for (int i=0; i<1; i++) {{}} | for (int i=0; i<1; i++) {{}} | Correct. | Java |
const data = 48; data = 49; | let data = 48; data = 49; | Cannot reassign const. | JavaScript |
items[35] | if (length(items) >= 35) items[35] | Check length. | R |
if (x = 24) | if (x == 24) | Use ==. | Scala |
$num = 4; if ($num = 4) {{}} | $num = 4; if ($num == 4) {{}} | Use ==. | PHP |
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