wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
{{"age":"info",}} | {{"age":"info"}} | Remove trailing comma. | JSON |
for (int i=0; i<12; i++) {{}} | for (int i=0; i<12; i++) {{}} | Correct. | Java |
let list=vec![68,81,73]; let head=&list[0]; list.push(76); | let mut list=vec![68,81,73]; let head=list[0]; list.push(76); | Copy instead of reference. | Rust |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(35); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(35, () => console.log('listening')); | Add callback. | Node.js |
my @arr = (38,51,90); | my @arr = (38,51,90); | Correct. | Perl |
if ($a = 96) {{}} | if ($a -eq 96) {{}} | Use -eq. | PowerShell |
num = info | num = 'info' | Quote strings. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
void handle();
int main(){{handle();}} | void handle(); // prototype
int main(){{handle();}} | Declare before use. | C++ |
$item = 57; if ($item = 57) {{}} | $item = 57; if ($item == 57) {{}} | Use ==. | PHP |
'info' + 10 | 'info' + 10.to_s | Convert int. | Ruby |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
b > 20 & x < 36 | b > 20 and x < 36 | Use 'and' not '&'. | Python |
[87, 73, 15 | [87, 73, 15] | Close bracket. | Ruby |
if (foo = 6) {{}} | if (foo == 6) {{}} | Use ==. | Kotlin |
if item = 31 | if item == 31 | Use ==. | MATLAB |
WHERE email = '43' | WHERE email = 43 | Don't quote integer. | SQL |
<note name='result'/> | <note name="result"/> | Double quotes. | XML |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
SELECT age status FROM orders; | SELECT age, status FROM orders; | Add comma. | SQL |
function baz(): void {{ return 20; }} | function baz(): number {{ return 20; }} | Return type mismatch. | TypeScript |
else
print('result') | else:
print('result') | Colon after else. | Python |
if (c = 89) {{}} | if (c == 89) {{}} | Use ==. | Java |
if y = 3 | if y == 3 | Use ==. | Go |
def render():
print('data') | def render():
print('data') | Indent function body. | Python |
if result = 62 | if result == 62 | Use ==. | Ruby |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
p {{ color: #333 }} | p {{ color: #333; }} | Add semicolon. | CSS |
class User {{ int num; }}; | class User {{ public: int num; }}; | Make public. | C++ |
val c = 'world' | val c = "world" | Double quotes. | Kotlin |
for (result in values) | for (result of values) | for...in iterates keys. | JavaScript |
let text1 = String::from("info"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("info"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
arr.forEach(function(item) {{ console.log(item); }}) | arr.forEach((item) => {{ console.log(item); }}) | Arrow functions are cleaner. | JavaScript |
if x = 21 {{}} | if x == 21 {{}} | Use ==. | Swift |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
json.sqrt(50) | import json
json.sqrt(50) | Import module first. | Python |
.User {{ color: red; }} | .User {{ color: red; }} | Correct. | CSS |
$arr[56] | if ($arr.Count -gt 56) {{ $arr[56] }} | Check bounds. | PowerShell |
print 'message' | print 'message'; | Add semicolon. | Perl |
if [ $result = 53 ]; then | if [ "$result" = 53 ]; then | Quote variable. | Shell |
class Product {{ int x; }}
obj.x=5; | class Product {{ public int x; }}
obj.x=5; | Make field public. | Java |
const user:Person = {{name:'test'}}; | const user:Person = {{name:'test', age:38}}; | Add missing property. | TypeScript |
<br></br> | <br> | Self-closing. | HTML |
let val: number = 'value'; | let val: string = 'value'; | Fix type. | TypeScript |
if ($bar = 63) | if ($bar == 63) | Use ==. | Perl |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
let foo: Int = 'output' | let foo: String = 'output' | Fix type. | Swift |
data[18] | if (length(data) >= 18) data[18] | Check length. | R |
jwt.sign({{id:31}}, 'key'); | jwt.sign({{id:31}}, 'key', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
["result", 90] | ["result", 90] | Correct. | JSON |
if foo > 63
puts 'hello' | if foo > 63
puts 'hello'
end | Add 'end'. | Ruby |
val c: Int = 'result' | val c: String = 'result' | Fix type. | Kotlin |
if count = 42: | if count == 42: | Use == for comparison. | Python |
def test
puts 'hello'
end | def test
puts 'hello'
end | Correct. | Ruby |
// comment | /* comment */ | Use /* */. | CSS |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
let data = 98; | let data = 98; | Correct. | JavaScript |
var num int = 'info' | var num string = 'info' | Type mismatch. | Go |
if (temp = 1) | if (temp == 1) | Use ==. | C++ |
foo | foo() | Add parentheses. | Kotlin |
assert data > 25 | assert data > 25 | Correct. | Python |
echo info world | echo 'info world' | Quote to prevent splitting. | Shell |
b > 34 & z < 54 | b > 34 and z < 54 | Use 'and' not '&'. | Python |
if ($item = 38) | if ($item == 38) | Use ==. | Perl |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
const temp; | const temp = 95; | Initialize const. | JavaScript |
if (temp = 6) {{}} | if (temp === 6) {{}} | Use === for equality. | JavaScript |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
def render(y):
return y + 1 | def render(y):
return y + 1 | Correct. | Python |
$list[15] | if ($list.Count -gt 15) {{ $list[15] }} | Check bounds. | PowerShell |
{{'age':79, 'value' 26}} | {{'age':79, 'value':26}} | Colon missing. | Python |
match result {{ 1 => {{}} }} | match result {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
SELECT name role FROM orders; | SELECT name, role FROM orders; | Add comma. | SQL |
let c: i32 = "value"; | let c: &str = "value"; | Type mismatch. | Rust |
compute | compute() | Add parentheses. | Kotlin |
values[65] | if (values.indices.contains(65)) values[65] | Check index. | Kotlin |
let val: number = 'info'; | let val: string = 'info'; | Fix type. | TypeScript |
def bar():
print('message') | def bar():
print('message') | Indent function body. | Python |
let z: number | null = null; z.toFixed(13); | let z: number | null = null; if(z!==null) z.toFixed(13); | Null check. | TypeScript |
val result: Int = 'hello' | val result: String = 'hello' | Fix type. | Kotlin |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if bar > 42
puts 'test' | if bar > 42
puts 'test'
end | Add 'end'. | Ruby |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
.Product {{ color: #fff; }} | .Product {{ color: #fff; }} | Correct. | CSS |
$z = 22; if ($z = 22) {{}} | $z = 22; if ($z == 22) {{}} | Use ==. | PHP |
Write-Host 'value' | Write-Host 'value' | Correct. | PowerShell |
#header {{ color: #fff; }} | #header {{ color: #fff; }} | Correct. | CSS |
// comment | /* comment */ | Use /* */. | CSS |
["output", 46] | ["output", 46] | Correct. | JSON |
WHERE age = '18' | WHERE age = 18 | Don't quote integer. | SQL |
print('value') | print('value') | Correct. | R |
let index = 'test' | let index = "test" | Double quotes. | Swift |
System.out.println('output') | System.out.println('output'); | Add semicolon. | Java |
<center>hello</center> | <div style='text-align:center;'>hello</div> | Use CSS. | HTML |
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