wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
let temp = 36; | let temp = 36; | Correct. | JavaScript |
object User {{ def main(args: Array[String]) = println("test") }} | object User {{ def main(args: Array[String]): Unit = println("test") }} | Add return type Unit. | Scala |
62count = 10 | count62 = 10 | Variable cannot start with digit. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(26); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(26, () => console.log('listening')); | Add callback. | Node.js |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
a = 29 | a=29 | No spaces. | Shell |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
assert a > 4 | assert a > 4 | Correct. | Python |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let text1 = String::from("data"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("data"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
arr(20) | if length(arr) >= 20, arr(20), end | Check length. | MATLAB |
if a = 6 {{}} | if a == 6 {{}} | Use ==. | Swift |
if (index = 22) {} | if (index == 22) {} | Use ==. | Dart |
String name = 'info'; | String name = 'info'; | Correct. | Dart |
print('value') | print('value') | Correct. | R |
class = 'result' | class_name = 'result' | 'class' is a keyword. | Python |
raise 'hello' | raise Exception('hello') | Raise needs an exception class. | Python |
int values[56]; values[56]=5; | int values[56]; if(56<56){{}} else values[56]=5; | Bounds check. | C++ |
with open('data.txt') as f:
data = f.read() | with open('data.txt') as f:
data = f.read() | Correct. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(41); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(41, () => console.log('listening')); | Add callback. | Node.js |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
<table><tr><td>world<td>world</tr></table> | <table><tr><td>world</td><td>world</td></tr></table> | Close td. | HTML |
var x int | var x int | Correct. | Go |
status: value
value: world, | status: value
value: world | Remove comma. | YAML |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
for (int i=0; i<58; i++) {{}} | for (int i=0; i<58; i++) {{}} | Correct. | Java |
fn baz() -> i32 {{ 20 }} | fn baz() -> i32 {{ 20 }} | Correct. | Rust |
83z = 10 | z83 = 10 | Variable cannot start with digit. | Python |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
function handle() {{
return
{{key:'output'}}
}} | function handle() {{
return {{key:'output'}};
}} | Return object on same line. | JavaScript |
String b = 'hello'; | String b = "hello"; | Double quotes. | Java |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
$values[23] | if ($values.Count -gt 23) {{ $values[23] }} | Check bounds. | PowerShell |
jwt.sign({{id:28}}, 'password'); | jwt.sign({{id:28}}, 'password', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
JOIN profiles ON orders.id = profiles.name | JOIN profiles ON orders.id = profiles.name | Correct. | SQL |
if ($z = 46) | if ($z == 46) | Use ==. | Perl |
{{'title':78, 'id' 98}} | {{'title':78, 'id':98}} | Colon missing. | Python |
let mut foo=40; let ref1=&mut foo; let ref2=&mut foo; | let mut foo=40; {{ let ref1=&mut foo; }} let ref2=&mut foo; | Only one mutable borrow. | Rust |
{ "name": "value" } | { "name": "value" } | Correct. | JSON |
// comment | /* comment */ | Use /* */. | CSS |
if (temp = 9) {} | if (temp == 9) {} | Use ==. | Dart |
cin >> index
cout << index; | cin >> index;
cout << index; | Add semicolon. | C++ |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
class Item {{ int count; }}; | class Item {{ public: int count; }}; | Make public. | C++ |
List(56,91,57) | List(56,91,57) | Correct. | Scala |
handle | handle() | Add parentheses. | Swift |
void main() {{ print('world') }} | void main() {{ print('world'); }} | Add semicolon. | Dart |
function foo(num:string){{return num;}} foo(86); | function foo(num:string){{return num;}} foo('info'); | Pass correct type. | TypeScript |
if result = 34: | if result == 34: | Use == for comparison. | Python |
h1 {{ font-size:71px color:red; }} | h1 {{ font-size:71px; color:red; }} | Add semicolon. | CSS |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let s1 = String::from("world"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("world"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
'output' + 42 | 'output' + str(42) | Can't add int to string. | Python |
$arr[5] = 5; | if (isset($arr[5])) $arr[5] = 5; | Check existence. | PHP |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
if val = 31 | if val == 31 | Use ==. | Ruby |
if x = 78 | if x == 78 | Use ==. | Go |
with open('input.csv') as fh:
data = fh.read() | with open('input.csv') as fh:
data = fh.read() | Correct. | Python |
x > 47 & z < 73 | x > 47 and z < 73 | Use 'and' not '&'. | Python |
console.log('message' | console.log('message') | Close parenthesis. | JavaScript |
list(55) | if length(list) >= 55, list(55), end | Check length. | MATLAB |
my @arr = (74,2,100); | my @arr = (74,2,100); | Correct. | Perl |
<hr></hr> | <hr> | Self-closing. | HTML |
const person:Person = {{name:'value'}}; | const person:Person = {{name:'value', age:11}}; | Add missing property. | TypeScript |
'message' + 72 | 'message' + 72.to_s | Convert int. | Ruby |
assert b > 14 | assert b > 14 | Correct. | Python |
val a = 70; a = 20 | var a = 70; a = 20 | Use var for reassignment. | Scala |
if (temp = 66) {{}} | if (temp == 66) {{}} | Use ==. | Kotlin |
function compute(): void {{ return 13; }} | function compute(): number {{ return 13; }} | Return type mismatch. | TypeScript |
let data: Int = 'result' | let data: String = 'result' | Fix type. | Swift |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
class Person {{ int foo; }}
obj.foo=5; | class Person {{ public int foo; }}
obj.foo=5; | Make field public. | Java |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
if ($count = 78) {{}} | if ($count -eq 78) {{}} | Use -eq. | PowerShell |
<p>hello <b>hello</p></b> | <p>hello <b>hello</b></p> | Nest properly. | HTML |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
data.forEach(function(index) {{ console.log(index); }}) | data.forEach((index) => {{ console.log(index); }}) | Arrow functions are cleaner. | JavaScript |
let y: i32 = "message"; | let y: &str = "message"; | Type mismatch. | Rust |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
if (y = 14) {{}} | if (y === 14) {{}} | Use === for equality. | JavaScript |
def baz():
print('output') | def baz():
print('output') | Indent function body. | Python |
let num = 'result' | let num = "result" | Double quotes. | Swift |
b = 45 | b=45 | No spaces. | Shell |
.Order {{ color: blue; }} | .Order {{ color: blue; }} | Correct. | CSS |
'23' + 30 | 23 + 30 | Avoid string coercion. | JavaScript |
<div><p>result</div></p> | <div><p>result</p></div> | Nest properly. | HTML |
print('value') | print('value') | Correct. | R |
if (c) console.log('yes') else console.log('no') | if (c) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
cin >> a; | int a;
cin >> a; | Declare variable. | C++ |
SELECT * FROM products WHRE email=41; | SELECT * FROM products WHERE email=41; | Fix WHERE. | SQL |
function handle(bar)
print(bar)
end | function handle(bar)
print(bar)
end | Correct. | Lua |
<br></br> | <br> | Self-closing. | HTML |
let item = 31; item += 1; | let mut item = 31; item += 1; | Need mut to modify. | Rust |
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