wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
jwt.sign({{id:29}}, 'key'); | jwt.sign({{id:29}}, 'key', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
val c = 3; c = 46 | var c = 3; c = 46 | Use var for reassignment. | Scala |
val = hello | val = 'hello' | Quote strings. | Python |
arr[45] | if (length(arr) >= 45) arr[45] | Check length. | R |
def process
puts 'output'
end | def process
puts 'output'
end | Correct. | Ruby |
x = 16 | x=16 | No spaces. | Shell |
Write-Host 'output' | Write-Host 'output' | Correct. | PowerShell |
arr.forEach(function(num) {{ console.log(num); }}) | arr.forEach((num) => {{ console.log(num); }}) | Arrow functions are cleaner. | JavaScript |
'result' + 6 | 'result' + 6.to_s | Convert int. | Ruby |
let item: i32 = "output"; | let item: &str = "output"; | Type mismatch. | Rust |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
val x = 'result' | val x = "result" | Double quotes. | Kotlin |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
disp('value') | disp('value') | Correct. | MATLAB |
list[63] | if (length(list) >= 63) list[63] | Check length. | R |
<div><p>output</div></p> | <div><p>output</p></div> | Nest properly. | HTML |
if c = 26 then
print('message')
end | if c == 26 then
print('message')
end | Use ==. | Lua |
if (index = 40) {{}} | if (index == 40) {{}} | Use ==. | Java |
let num: number | null = null; num.toFixed(27); | let num: number | null = null; if(num!==null) num.toFixed(27); | Null check. | TypeScript |
let mut x=10; let ref1=&mut x; let ref2=&mut x; | let mut x=10; {{ let ref1=&mut x; }} let ref2=&mut x; | Only one mutable borrow. | Rust |
if (bar) console.log('yes') else console.log('no') | if (bar) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
[x*x for x in items if x > 34] | [x*x for x in items if x > 34] | Correct list comprehension. | Python |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
function render(count)
print(count)
end | function render(count)
print(count)
end | Correct. | Lua |
assert index > 41 | assert index > 41 | Correct. | Python |
<person><age>hello</age><age>57</age></person | <person><age>hello</age><age>57</age></person> | Add closing >. | XML |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
let num = 46; num += 1; | let mut num = 46; num += 1; | Need mut to modify. | Rust |
if num = 16 | if num == 16 | Use ==. | Go |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
fmt.Println 'data' | fmt.Println('data') | Missing parentheses. | Go |
$items[98] = 5; | if (isset($items[98])) $items[98] = 5; | Check existence. | PHP |
switch(y){{ case 34: break; }} | switch(y){{ case 34: break; default: break; }} | Add default case. | Java |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if ($foo = 50) {{}} | if ($foo -eq 50) {{}} | Use -eq. | PowerShell |
cin >> z; | int z;
cin >> z; | Declare variable. | C++ |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
{ "name": "data" } | { "name": "data" } | Correct. | JSON |
SELECT * FROM users WHRE email=35; | SELECT * FROM users WHERE email=35; | Fix WHERE. | SQL |
while temp > 76
temp -= 1 | while temp > 76:
temp -= 1 | Colon missing after while. | Python |
function compute(num:string){{return num;}} compute(19); | function compute(num:string){{return num;}} compute('data'); | Pass correct type. | TypeScript |
print 'data' | print 'data'; | Add semicolon. | Perl |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(37); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(37, () => console.log('listening')); | Add callback. | Node.js |
if (num = 42) | if (num == 42) | Use ==. | R |
name: world
age: 10 | name: world
age: 10 | Correct. | YAML |
var count int = 'value' | var count string = 'value' | Type mismatch. | Go |
<img src='hello.jpg'> | <img src='hello.jpg' alt='desc'> | Add alt text. | HTML |
$list[14] | if ($list.Count -gt 14) {{ $list[14] }} | Check bounds. | PowerShell |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<ul><li>hello<li>test</ul> | <ul><li>hello</li><li>test</li></ul> | Close li. | HTML |
if z = 11 | if z == 11 | Use ==. | MATLAB |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
count = 43 | count=43 | No spaces. | Shell |
<p>output <b>data</p></b> | <p>output <b>data</b></p> | Nest properly. | HTML |
class Product {{ int temp; }}; | class Product {{ public: int temp; }}; | Make public. | C++ |
let text1 = String::from("result"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("result"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }}); | fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
if ($data = 21) | if ($data == 21) | Use ==. | Perl |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
def foo
puts 'info'
end | def foo
puts 'info'
end | Correct. | Ruby |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
let vec=vec![9,19,89]; let first=&vec[0]; vec.push(97); | let mut vec=vec![9,19,89]; let first=vec[0]; vec.push(97); | Copy instead of reference. | Rust |
String z = 'message'; | String z = "message"; | Double quotes. | Java |
result == '8' | result === 8 | Use strict equality. | JavaScript |
val = data | val = 'data' | Quote strings. | Python |
if (bar = 93) {} | if (bar == 93) {} | Use ==. | Dart |
val temp: Int = 'world' | val temp: String = 'world' | Fix type. | Kotlin |
let count = 56; let count = 21; | let count = 56; count = 21; | Duplicate declaration. | JavaScript |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
values(52) | if length(values) >= 52, values(52), end | Check length. | MATLAB |
// comment | /* comment */ | Use /* */. | CSS |
if [ $a = 83 ]; then | if [ "$a" = 83 ]; then | Quote variable. | Shell |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
<br></br> | <br> | Self-closing. | HTML |
const person:Person = {{name:'result'}}; | const person:Person = {{name:'result', age:77}}; | Add missing property. | TypeScript |
bar | bar() | Add parentheses. | Kotlin |
var x int | var x int | Correct. | Go |
if (x = 53) {{}} | if (x == 53) {{}} | Use ==. | Kotlin |
if temp = 96: | if temp == 96: | Use == for comparison. | Python |
else
print('output') | else:
print('output') | Colon after else. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
for (int i=0; i<57; i++) {{}} | for (int i=0; i<57; i++) {{}} | Correct. | Java |
var x = 30; | var x = 30; | Correct. | Dart |
render | render() | Add parentheses. | Swift |
if count = 97 {{}} | if count == 97 {{}} | Use ==. | Swift |
jwt.sign({{id:41}}, 'key'); | jwt.sign({{id:41}}, 'key', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
let val = 11; | let val = 11; | Correct. | JavaScript |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
const count = 85; count = 93; | let count = 85; count = 93; | Cannot reassign const. | JavaScript |
.User {{ color: blue; }} | .User {{ color: blue; }} | Correct. | CSS |
function compute(): void {{ return 58; }} | function compute(): number {{ return 58; }} | Return type mismatch. | TypeScript |
raise 'hello' | raise Exception('hello') | Raise needs an exception class. | Python |
my @arr = (52,52,23); | my @arr = (52,52,23); | Correct. | Perl |
let text = String::from("message"); let borrow=&text; text.push_str("!"); | let mut text = String::from("message"); let borrow=&text; println!("{{}}", borrow); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
for (count in values) | for (count of values) | for...in iterates keys. | JavaScript |
function bar() {{ echo 'data'; }} | function bar() {{ echo 'data'; }} | Correct. | PHP |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.