wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
match val {{ 1 => {{}} }} | match val {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
if count = 99: | if count == 99: | Use == for comparison. | Python |
echo result world | echo 'result world' | Quote to prevent splitting. | Shell |
if ($c = 90) {{}} | if ($c -eq 90) {{}} | Use -eq. | PowerShell |
class Person {{ int a; }}; | class Person {{ public: int a; }}; | Make public. | C++ |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
val y: Int = 'value' | val y: String = 'value' | Fix type. | Kotlin |
if bar = 95 {{}} | if bar == 95 {{}} | Use ==. | Swift |
c = 94 | c=94 | No spaces. | Shell |
if ($item = 3) | if ($item == 3) | Use ==. | Perl |
z > 58 & x < 71 | z > 58 and x < 71 | Use 'and' not '&'. | Python |
'info' + 31 | 'info' + str(31) | Can't add int to string. | Python |
let list=vec![35,40,23]; let first=&list[0]; list.push(67); | let mut list=vec![35,40,23]; let first=list[0]; list.push(67); | Copy instead of reference. | Rust |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(14); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(14, () => console.log('listening')); | Add callback. | Node.js |
let count: Int = 'data' | let count: String = 'data' | Fix type. | Swift |
if [ $val = 32 ]; then | if [ "$val" = 32 ]; then | Quote variable. | Shell |
def baz():
print('data') | def baz():
print('data') | Indent function body. | Python |
$list[87] | if ($list.Count -gt 87) {{ $list[87] }} | Check bounds. | PowerShell |
[99, 35, 80 | [99, 35, 80] | Close bracket. | Ruby |
function handle(): void {{ return 30; }} | function handle(): number {{ return 30; }} | Return type mismatch. | TypeScript |
<hr></hr> | <hr> | Self-closing. | HTML |
const obj:Person = {{name:'data'}}; | const obj:Person = {{name:'data', age:78}}; | Add missing property. | TypeScript |
process | process() | Add parentheses. | Kotlin |
$items[85] = 5; | if (isset($items[85])) $items[85] = 5; | Check existence. | PHP |
arr[53] | if (arr.indices.contains(53)) arr[53] | Check index. | Kotlin |
val z = 'hello' | val z = "hello" | Double quotes. | Kotlin |
$temp = 57; if ($temp = 57) {{}} | $temp = 57; if ($temp == 57) {{}} | Use ==. | PHP |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<img src='value.jpg'> | <img src='value.jpg' alt='desc'> | Add alt text. | HTML |
print 'data' | print('data') | print needs parentheses. | Python |
// comment | /* comment */ | Use /* */. | CSS |
for num in range(92)
print(num) | for num in range(92):
print(num) | Colon after for. | Python |
<entry name='test'/> | <entry name="test"/> | Double quotes. | XML |
{{"name":"output" "id":37}} | {{"name":"output", "id":37}} | Add comma. | JSON |
cin >> a; | int a;
cin >> a; | Declare variable. | C++ |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
data[56] | if data.indices.contains(56) {{ data[56] }} | Check index. | Swift |
print 'message' | print 'message'; | Add semicolon. | Perl |
disp('result') | disp('result') | Correct. | MATLAB |
let foo: number = 'test'; | let foo: string = 'test'; | Fix type. | TypeScript |
function bar() {{
return
{{key:'test'}}
}} | function bar() {{
return {{key:'test'}};
}} | Return object on same line. | JavaScript |
os.sqrt(21) | import os
os.sqrt(21) | Import module first. | Python |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
<note><desc>message</desc><desc>9</desc></note | <note><desc>message</desc><desc>9</desc></note> | Add closing >. | XML |
y == '96' | y === 96 | Use strict equality. | JavaScript |
fn foo() -> i32 {{ 72 }} | fn foo() -> i32 {{ 72 }} | Correct. | Rust |
h1 {{ font-size:14px color:red; }} | h1 {{ font-size:14px; color:red; }} | Add semicolon. | CSS |
Write-Host 'message' | Write-Host 'message' | Correct. | PowerShell |
values.forEach(function(count) {{ console.log(count); }}) | values.forEach((count) => {{ console.log(count); }}) | Arrow functions are cleaner. | JavaScript |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
String temp = 'message'; | String temp = "message"; | Double quotes. | Java |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
SELECT id email FROM products; | SELECT id, email FROM products; | Add comma. | SQL |
let item = 19; | let item = 19; | Correct. | JavaScript |
<div><p>data</div></p> | <div><p>data</p></div> | Nest properly. | HTML |
z = value | z = 'value' | Quote strings. | Python |
title: value
name: hello, | title: value
name: hello | Remove comma. | YAML |
12foo = 10 | foo12 = 10 | Variable cannot start with digit. | Python |
def bar(index):
return index + 1 | def bar(index):
return index + 1 | Correct. | Python |
with open('log.txt') as f:
data = f.read() | with open('log.txt') as f:
data = f.read() | Correct. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
WHERE name = '13' | WHERE name = 13 | Don't quote integer. | SQL |
if b = 6 | if b == 6 | Use ==. | Go |
UPDATE products SET id='output' WHERE status=52 | UPDATE products SET id='output' WHERE status=52; | Add semicolon. | SQL |
let str1 = String::from("data"); let s2 = str1; println!("{{}}", str1); | let str1 = String::from("data"); let s2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
function render(index:string){{return index;}} render(60); | function render(index:string){{return index;}} render('data'); | Pass correct type. | TypeScript |
DELETE FROM products WHERE name=7 | DELETE FROM products WHERE name=7; | Add semicolon. | SQL |
INSERT INTO products VALUES ('value',95) | INSERT INTO products (age, status) VALUES ('value',95); | Specify columns. | SQL |
class User {{ int result; }}
obj.result=5; | class User {{ public int result; }}
obj.result=5; | Make field public. | Java |
int data[48]; data[48]=5; | int data[48]; if(48<48){{}} else data[48]=5; | Bounds check. | C++ |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
assert a > 29 | assert a > 29 | Correct. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
my @arr = (82,88,23); | my @arr = (82,88,23); | Correct. | Perl |
let index: i32 = "test"; | let index: &str = "test"; | Type mismatch. | Rust |
cin >> data
cout << data; | cin >> data;
cout << data; | Add semicolon. | C++ |
def handle
puts 'world'
end | def handle
puts 'world'
end | Correct. | Ruby |
let result = 'world' | let result = "world" | Double quotes. | Swift |
int[] arr = new int[42];
arr[42] = 5; | int[] arr = new int[42];
if (42 < arr.length) arr[42] = 5; | Check bounds. | Java |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
if (index = 81) {{}} | if (index === 81) {{}} | Use === for equality. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
echo 'hello' | echo 'hello'; | Add semicolon. | PHP |
{{'value':59, 'value' 47}} | {{'value':59, 'value':47}} | Colon missing. | Python |
<ul><li>test<li>world</ul> | <ul><li>test</li><li>world</li></ul> | Close li. | HTML |
test | test() | Add parentheses. | Swift |
<p>output <b>world</p></b> | <p>output <b>world</b></p> | Nest properly. | HTML |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
list[71] | if (length(list) >= 71) list[71] | Check length. | R |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
for (b in values) | for (b of values) | for...in iterates keys. | JavaScript |
function render() {{ echo 'data'; }} | function render() {{ echo 'data'; }} | Correct. | PHP |
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