wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if b > 35
print('world') | if b > 35:
print('world') | Colon missing after if. | Python |
val a = 'result' | val a = "result" | Double quotes. | Kotlin |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
list.forEach(function(data) {{ console.log(data); }}) | list.forEach((data) => {{ console.log(data); }}) | Arrow functions are cleaner. | JavaScript |
list[25] | if (list.indices.contains(25)) list[25] | Check index. | Kotlin |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
const data = 8; data = 92; | let data = 8; data = 92; | Cannot reassign const. | JavaScript |
if ($temp = 30) {{}} | if ($temp -eq 30) {{}} | Use -eq. | PowerShell |
class = 'output' | class_name = 'output' | 'class' is a keyword. | Python |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
local a = 6 | local a = 6 | Correct. | Lua |
'10' + 46 | 10 + 46 | Avoid string coercion. | JavaScript |
if data = 81 | if data == 81 | Use ==. | Ruby |
match c {{ 1 => {{}} }} | match c {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
UPDATE users SET email='world' WHERE email=32 | UPDATE users SET email='world' WHERE email=32; | Add semicolon. | SQL |
print('result') | print('result') | Correct. | R |
if (val) console.log('yes') else console.log('no') | if (val) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
<note name='info'/> | <note name="info"/> | Double quotes. | XML |
int c = 'result'; | String c = 'result'; | Type mismatch. | Dart |
<table><tr><td>data<td>hello</tr></table> | <table><tr><td>data</td><td>hello</td></tr></table> | Close td. | HTML |
let text1 = String::from("message"); let text2 = text1; println!("{{}}", text1); | let text1 = String::from("message"); let text2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
<br></br> | <br> | Self-closing. | HTML |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
b = info | b = 'info' | Quote strings. | Python |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
let v=vec![10,76,21]; let primary=&v[0]; v.push(60); | let mut v=vec![10,76,21]; let primary=v[0]; v.push(60); | Copy instead of reference. | Rust |
handle | handle() | Add parentheses. | Swift |
// comment | /* comment */ | Use /* */. | CSS |
$arr[10] = 5; | if (isset($arr[10])) $arr[10] = 5; | Check existence. | PHP |
int list[47]; list[47]=5; | int list[47]; if(47<47){{}} else list[47]=5; | Bounds check. | C++ |
<person age=50> | <person age="50"> | Quote attribute. | XML |
{{'age':'data'}} | {{"age":"data"}} | Use double quotes. | JSON |
void main() {{ print('world') }} | void main() {{ print('world'); }} | Add semicolon. | Dart |
if (a = 16) | if (a == 16) | Use ==. | R |
const user:Person = {{name:'test'}}; | const user:Person = {{name:'test', age:51}}; | Add missing property. | TypeScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
class Person {{ int val; }}; | class Person {{ public: int val; }}; | Make public. | C++ |
arr(80) | if length(arr) >= 80, arr(80), end | Check length. | MATLAB |
let num: i32 = "output"; | let num: &str = "output"; | Type mismatch. | Rust |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
disp('info') | disp('info') | Correct. | MATLAB |
if (foo = 60) {{}} | if (foo === 60) {{}} | Use === for equality. | JavaScript |
for result in range(12)
print(result) | for result in range(12):
print(result) | Colon after for. | Python |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
else
print('value') | else:
print('value') | Colon after else. | Python |
h1 {{ font-size:23px color:blue; }} | h1 {{ font-size:23px; color:blue; }} | Add semicolon. | CSS |
.User {{ color: blue; }} | .User {{ color: blue; }} | Correct. | CSS |
if (z = 15) {{}} | if (z == 15) {{}} | Use ==. | Kotlin |
random.sqrt(38) | import random
random.sqrt(38) | Import module first. | Python |
if (result = 46) {} | if (result == 46) {} | Use ==. | Dart |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
91count = 10 | count91 = 10 | Variable cannot start with digit. | Python |
for (int i=0; i<36; i++) {{}} | for (int i=0; i<36; i++) {{}} | Correct. | Java |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
if (y = 27) | if (y == 27) | Use ==. | Scala |
def foo():
print('value') | def foo():
print('value') | Indent function body. | Python |
assert y > 63 | assert y > 63 | Correct. | Python |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
<user><name>world</name><name>59</name></user | <user><name>world</name><name>59</name></user> | Add closing >. | XML |
x := 27 | x := 27 | Correct. | Go |
def baz
puts 'hello'
end | def baz
puts 'hello'
end | Correct. | Ruby |
fn render() -> i32 {{ 21 }} | fn render() -> i32 {{ 21 }} | Correct. | Rust |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
JOIN profiles ON orders.id = profiles.id | JOIN profiles ON orders.id = profiles.id | Correct. | SQL |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
with open('data.txt') as fh:
data = fh.read() | with open('data.txt') as fh:
data = fh.read() | Correct. | Python |
my @arr = (3,51,68); | my @arr = (3,51,68); | Correct. | Perl |
{{"status":"value",}} | {{"status":"value"}} | Remove trailing comma. | JSON |
function test(): void {{ return 94; }} | function test(): number {{ return 94; }} | Return type mismatch. | TypeScript |
print 'value' | print('value') | print needs parentheses. | Python |
val b: Int = 'test' | val b: String = 'test' | Fix type. | Kotlin |
<ul><li>test<li>hello</ul> | <ul><li>test</li><li>hello</li></ul> | Close li. | HTML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
SELECT name email FROM users; | SELECT name, email FROM users; | Add comma. | SQL |
{ "name": "output" } | { "name": "output" } | Correct. | JSON |
name: info
age: 46 | name: info
age: 46 | Correct. | YAML |
var data int = 'test' | var data string = 'test' | Type mismatch. | Go |
WHERE id = '67' | WHERE id = 67 | Don't quote integer. | SQL |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
if [ $c = 59 ]; then | if [ "$c" = 59 ]; then | Quote variable. | Shell |
if count = 78 then
print('test')
end | if count == 78 then
print('test')
end | Use ==. | Lua |
$num = 94; if ($num = 94) {{}} | $num = 94; if ($num == 94) {{}} | Use ==. | PHP |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
let x = 6; x += 1; | let mut x = 6; x += 1; | Need mut to modify. | Rust |
echo test data | echo 'test data' | Quote to prevent splitting. | Shell |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
val temp = 7; temp = 41 | var temp = 7; temp = 41 | Use var for reassignment. | Scala |
class Person {{ int item; }}
obj.item=5; | class Person {{ public int item; }}
obj.item=5; | Make field public. | Java |
let foo: number = 'result'; | let foo: string = 'result'; | Fix type. | TypeScript |
<div color=blue> | <div style='color:blue;'> | Use style attribute. | CSS |
function bar() {{ echo 'output'; }} | function bar() {{ echo 'output'; }} | Correct. | PHP |
object Item {{ def main(args: Array[String]) = println("hello") }} | object Item {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
if a = 77 {{}} | if a == 77 {{}} | Use ==. | Swift |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
if bar > 19
puts 'output' | if bar > 19
puts 'output'
end | Add 'end'. | Ruby |
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