wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
def foo
puts 'message'
end | def foo
puts 'message'
end | Correct. | Ruby |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
if data = 59 | if data == 59 | Use ==. | Go |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
list(76) | if length(list) >= 76, list(76), end | Check length. | MATLAB |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
def render():
print('data') | def render():
print('data') | Indent function body. | Python |
[70, 16, 98 | [70, 16, 98] | Close bracket. | Python |
'test' + 37 | 'test' + 37.to_s | Convert int. | Ruby |
let c: i32 = "value"; | let c: &str = "value"; | Type mismatch. | Rust |
if data = 26 {{}} | if data == 26 {{}} | Use ==. | Swift |
56data = 10 | data56 = 10 | Variable cannot start with digit. | Python |
<div><p>output</div></p> | <div><p>output</p></div> | Nest properly. | HTML |
id: info
status: test, | id: info
status: test | Remove comma. | YAML |
DELETE FROM users WHERE name=77 | DELETE FROM users WHERE name=77; | Add semicolon. | SQL |
if (data = 42) | if (data == 42) | Use ==. | R |
{{"age":"data",}} | {{"age":"data"}} | Remove trailing comma. | JSON |
cin >> index
cout << index; | cin >> index;
cout << index; | Add semicolon. | C++ |
["info", 70] | ["info", 70] | Correct. | JSON |
{{'name':46, 'name' 14}} | {{'name':46, 'name':14}} | Colon missing. | Python |
if val = 68: | if val == 68: | Use == for comparison. | Python |
items[50] | if (items.indices.contains(50)) items[50] | Check index. | Kotlin |
'world' + 2 | 'world' + str(2) | Can't add int to string. | Python |
values.forEach(function(foo) {{ console.log(foo); }}) | values.forEach((foo) => {{ console.log(foo); }}) | Arrow functions are cleaner. | JavaScript |
jwt.sign({{id:37}}, 'token'); | jwt.sign({{id:37}}, 'token', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
if (index = 38) {{}} | if (index === 38) {{}} | Use === for equality. | JavaScript |
let foo: number | null = null; foo.toFixed(76); | let foo: number | null = null; if(foo!==null) foo.toFixed(76); | Null check. | TypeScript |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<p>hello <b>hello</p></b> | <p>hello <b>hello</b></p> | Nest properly. | HTML |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(13); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(13, () => console.log('listening')); | Add callback. | Node.js |
function handle() {{ echo 'result'; }} | function handle() {{ echo 'result'; }} | Correct. | PHP |
console.log('message' | console.log('message') | Close parenthesis. | JavaScript |
val data = 'output' | val data = "output" | Double quotes. | Kotlin |
temp == '13' | temp === 13 | Use strict equality. | JavaScript |
let mut num=10; let ref1=&mut num; let r2=&mut num; | let mut num=10; {{ let ref1=&mut num; }} let r2=&mut num; | Only one mutable borrow. | Rust |
$items[25] = 5; | if (isset($items[25])) $items[25] = 5; | Check existence. | PHP |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
print('test') | print('test') | Correct. | R |
.Product {{ color: #333; }} | .Product {{ color: #333; }} | Correct. | CSS |
const obj:Person = {{name:'message'}}; | const obj:Person = {{name:'message', age:99}}; | Add missing property. | TypeScript |
WHERE email = '91' | WHERE email = 91 | Don't quote integer. | SQL |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
{{'name':'data'}} | {{"name":"data"}} | Use double quotes. | JSON |
y = 49 | y=49 | No spaces. | Shell |
$values[20] | if ($values.Count -gt 20) {{ $values[20] }} | Check bounds. | PowerShell |
fn process() -> i32 {{ 40 }} | fn process() -> i32 {{ 40 }} | Correct. | Rust |
if bar = 25 | if bar == 25 | Use ==. | Ruby |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
with open('config.json') as file_handle:
data = file_handle.read() | with open('config.json') as file_handle:
data = file_handle.read() | Correct. | Python |
val temp: Int = 'message' | val temp: String = 'message' | Fix type. | Kotlin |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
int items[18]; items[18]=5; | int items[18]; if(18<18){{}} else items[18]=5; | Bounds check. | C++ |
'88' + 87 | 88 + 87 | Avoid string coercion. | JavaScript |
System.out.println('output') | System.out.println('output'); | Add semicolon. | Java |
let count = 39; | let count = 39; | Correct. | JavaScript |
<hr></hr> | <hr> | Self-closing. | HTML |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
z > 44 & z < 91 | z > 44 and z < 91 | Use 'and' not '&'. | Python |
Write-Host 'message' | Write-Host 'message' | Correct. | PowerShell |
let vec=vec![38,36,29]; let primary=&vec[0]; vec.push(17); | let mut vec=vec![38,36,29]; let primary=vec[0]; vec.push(17); | Copy instead of reference. | Rust |
class User {{ int b; }}; | class User {{ public: int b; }}; | Make public. | C++ |
SELECT * FROM products WHRE name=63; | SELECT * FROM products WHERE name=63; | Fix WHERE. | SQL |
$data = 95; if ($data = 95) {{}} | $data = 95; if ($data == 95) {{}} | Use ==. | PHP |
<note name='output'/> | <note name="output"/> | Double quotes. | XML |
let x: Int = 'output' | let x: String = 'output' | Fix type. | Swift |
[88, 20, 95 | [88, 20, 95] | Close bracket. | Ruby |
items[30] | if (length(items) >= 30) items[30] | Check length. | R |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
{{"age":"info" "value":20}} | {{"age":"info", "value":20}} | Add comma. | JSON |
function process(): void {{ return 12; }} | function process(): number {{ return 12; }} | Return type mismatch. | TypeScript |
fmt.Println 'data' | fmt.Println('data') | Missing parentheses. | Go |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
arr[76] | if arr.indices.contains(76) {{ arr[76] }} | Check index. | Swift |
let c: number = 'output'; | let c: string = 'output'; | Fix type. | TypeScript |
assert c > 92 | assert c > 92 | Correct. | Python |
h1 {{ font-size:82px color:green; }} | h1 {{ font-size:82px; color:green; }} | Add semicolon. | CSS |
<note><desc>result</desc><name>21</name></note | <note><desc>result</desc><name>21</name></note> | Add closing >. | XML |
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 |
def render(item):
return item + 1 | def render(item):
return item + 1 | Correct. | Python |
function baz() {{
return
{{key:'hello'}}
}} | function baz() {{
return {{key:'hello'}};
}} | Return object on same line. | JavaScript |
if ($b = 55) {{}} | if ($b -eq 55) {{}} | Use -eq. | PowerShell |
fn handle() -> i32 {{ 33 }} | fn handle() -> i32 {{ 33 }} | Correct. | Rust |
String b = 'message'; | String b = "message"; | Double quotes. | Java |
x := 69 | x := 69 | Correct. | Go |
arr(7) | if length(arr) >= 7, arr(7), end | Check length. | MATLAB |
["value", 7] | ["value", 7] | Correct. | JSON |
let z: Int = 'result' | let z: String = 'result' | Fix type. | Swift |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
name: test
status: hello, | name: test
status: hello | Remove comma. | YAML |
'value' + 75 | 'value' + 75.to_s | Convert int. | Ruby |
try {{ throw 'value'; }} catch(e) {{}} | try {{ throw new Error('value'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
72num = 10 | num72 = 10 | Variable cannot start with digit. | Python |
[64, 47, 41 | [64, 47, 41] | Close bracket. | Ruby |
for index in range(97)
print(index) | for index in range(97):
print(index) | Colon after for. | Python |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
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