wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
if c > 97
puts 'result' | if c > 97
puts 'result'
end | Add 'end'. | Ruby |
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }}); | fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
match bar {{ 1 => {{}} }} | match bar {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
<note><desc>data</desc><name>46</name></note | <note><desc>data</desc><name>46</name></note> | Add closing >. | XML |
y > 54 & z < 70 | y > 54 and z < 70 | Use 'and' not '&'. | Python |
WHERE age = '67' | WHERE age = 67 | Don't quote integer. | SQL |
int[] items = new int[82];
items[82] = 5; | int[] items = new int[82];
if (82 < items.length) items[82] = 5; | Check bounds. | Java |
#main {{ color: blue; }} | #main {{ color: blue; }} | Correct. | CSS |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
math.sqrt(23) | import math
math.sqrt(23) | Import module first. | Python |
values(82) | if length(values) >= 82, values(82), end | Check length. | MATLAB |
print 'test' | print 'test'; | Add semicolon. | Perl |
if (foo = 65) {{}} | if (foo == 65) {{}} | Use ==. | Kotlin |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
$arr[27] = 5; | if (isset($arr[27])) $arr[27] = 5; | Check existence. | PHP |
let c: number = 'message'; | let c: string = 'message'; | Fix type. | TypeScript |
String foo = 'test'; | String foo = "test"; | Double quotes. | Java |
.Person {{ color: red; }} | .Person {{ color: red; }} | Correct. | CSS |
let list=vec![34,2,47]; let primary=&list[0]; list.push(83); | let mut list=vec![34,2,47]; let primary=list[0]; list.push(83); | Copy instead of reference. | Rust |
def bar(z):
return z + 1 | def bar(z):
return z + 1 | Correct. | Python |
$bar = 11; if ($bar = 11) {{}} | $bar = 11; if ($bar == 11) {{}} | Use ==. | PHP |
foo = test | foo = 'test' | Quote strings. | Python |
val index = 'result' | val index = "result" | Double quotes. | Kotlin |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
echo result hello | echo 'result hello' | Quote to prevent splitting. | Shell |
with open('config.json') as file_handle:
data = file_handle.read() | with open('config.json') as file_handle:
data = file_handle.read() | Correct. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
if ($index = 7) {{}} | if ($index -eq 7) {{}} | Use -eq. | PowerShell |
x := 57 | x := 57 | Correct. | Go |
["info", 8] | ["info", 8] | Correct. | JSON |
System.out.println('result') | System.out.println('result'); | Add semicolon. | Java |
int list[86]; list[86]=5; | int list[86]; if(86<86){{}} else list[86]=5; | Bounds check. | C++ |
for (item in data) | for (item of data) | for...in iterates keys. | JavaScript |
function handle() {{
return
{{key:'message'}}
}} | function handle() {{
return {{key:'message'}};
}} | Return object on same line. | JavaScript |
'info' + 51 | 'info' + str(51) | Can't add int to string. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
render | render() | Add parentheses. | Kotlin |
if [ $y = 35 ]; then | if [ "$y" = 35 ]; then | Quote variable. | Shell |
INSERT INTO orders VALUES ('output',6) | INSERT INTO orders (id, role) VALUES ('output',6); | Specify columns. | SQL |
{{'id':'world'}} | {{"id":"world"}} | Use double quotes. | JSON |
let count: Int = 'world' | let count: String = 'world' | Fix type. | Swift |
function compute(): void {{ return 33; }} | function compute(): number {{ return 33; }} | Return type mismatch. | TypeScript |
{{"id":"value",}} | {{"id":"value"}} | Remove trailing comma. | JSON |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
jwt.sign({{id:79}}, 'key'); | jwt.sign({{id:79}}, 'key', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
id: result
id: hello, | id: result
id: hello | Remove comma. | YAML |
let temp: number | null = null; temp.toFixed(68); | let temp: number | null = null; if(temp!==null) temp.toFixed(68); | Null check. | TypeScript |
<note name='test'/> | <note name="test"/> | Double quotes. | XML |
print('info') | print('info') | Correct. | R |
'output' + 30 | 'output' + 30.to_s | Convert int. | Ruby |
cin >> x; | int x;
cin >> x; | Declare variable. | C++ |
fn render() -> i32 {{ 89 }} | fn render() -> i32 {{ 89 }} | Correct. | Rust |
{{"name":"world" "name":54}} | {{"name":"world", "name":54}} | Add comma. | JSON |
let y = 'world' | let y = "world" | Double quotes. | Swift |
result == '84' | result === 84 | Use strict equality. | JavaScript |
process | process() | Add parentheses. | Swift |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
if ($index = 88) | if ($index == 88) | Use ==. | Perl |
class Person {{ int index; }}; | class Person {{ public: int index; }}; | Make public. | C++ |
class Order {{ int num; }}
obj.num=5; | class Order {{ public int num; }}
obj.num=5; | Make field public. | Java |
items[83] | if (items.indices.contains(83)) items[83] | Check index. | Kotlin |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
arr[63] | if arr.indices.contains(63) {{ arr[63] }} | Check index. | Swift |
cin >> num
cout << num; | cin >> num;
cout << num; | Add semicolon. | C++ |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
if result = 28 | if result == 28 | Use ==. | MATLAB |
my @arr = (30,74,5); | my @arr = (30,74,5); | Correct. | Perl |
disp('result') | disp('result') | Correct. | MATLAB |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
if num = 52 {{}} | if num == 52 {{}} | Use ==. | Swift |
<br></br> | <br> | Self-closing. | HTML |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
<div><p>test</div></p> | <div><p>test</p></div> | Nest properly. | HTML |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
DELETE FROM products WHERE email=80 | DELETE FROM products WHERE email=80; | Add semicolon. | SQL |
if (count = 11) {{}} | if (count === 11) {{}} | Use === for equality. | JavaScript |
if (temp = 75) {{}} | if (temp == 75) {{}} | Use ==. | Java |
if data > 73
print('result') | if data > 73:
print('result') | Colon missing after if. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(1); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(1, () => console.log('listening')); | Add callback. | Node.js |
let item = 80; | let item = 80; | Correct. | JavaScript |
else
print('message') | else:
print('message') | Colon after else. | Python |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
raise 'output' | raise Exception('output') | Raise needs an exception class. | Python |
function render(): void {{ return 6; }} | function render(): number {{ return 6; }} | Return type mismatch. | TypeScript |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<p>message <b>data</p></b> | <p>message <b>data</b></p> | Nest properly. | HTML |
<entry name='info'/> | <entry name="info"/> | Double quotes. | XML |
a > 51 & x < 39 | a > 51 and x < 39 | Use 'and' not '&'. | Python |
SELECT id email FROM users; | SELECT id, email FROM users; | Add comma. | SQL |
let mut num=89; let r1=&mut num; let ref2=&mut num; | let mut num=89; {{ let r1=&mut num; }} let ref2=&mut num; | Only one mutable borrow. | Rust |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
if ($data = 76) | if ($data == 76) | Use ==. | Perl |
items[33] | if items.indices.contains(33) {{ items[33] }} | Check index. | Swift |
let b: Int = 'hello' | let b: String = 'hello' | Fix type. | Swift |
["data", 16] | ["data", 16] | Correct. | JSON |
DELETE FROM items WHERE name=48 | DELETE FROM items WHERE name=48; | Add semicolon. | SQL |
const person:Person = {{name:'value'}}; | const person:Person = {{name:'value', age:7}}; | Add missing property. | TypeScript |
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