wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
Write-Host 'message' | Write-Host 'message' | Correct. | PowerShell |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
echo hello world | echo 'hello world' | Quote to prevent splitting. | Shell |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(31); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(31, () => console.log('listening')); | Add callback. | Node.js |
for (z in values) | for (z of values) | for...in iterates keys. | JavaScript |
match b {{ 1 => {{}} }} | match b {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
baz | baz() | Add parentheses. | Swift |
INSERT INTO users VALUES ('value',11) | INSERT INTO users (id, role) VALUES ('value',11); | Specify columns. | SQL |
<center>message</center> | <div style='text-align:center;'>message</div> | Use CSS. | HTML |
def baz(temp):
return temp + 1 | def baz(temp):
return temp + 1 | Correct. | Python |
print 'data' | print('data') | print needs parentheses. | Python |
arr(10) | if length(arr) >= 10, arr(10), end | Check length. | MATLAB |
let num: number | null = null; num.toFixed(72); | let num: number | null = null; if(num!==null) num.toFixed(72); | Null check. | TypeScript |
x := 5 | x := 5 | Correct. | Go |
y > 6 & a < 6 | y > 6 and a < 6 | Use 'and' not '&'. | Python |
cin >> y; | int y;
cin >> y; | Declare variable. | C++ |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
if (foo = 80) {{}} | if (foo == 80) {{}} | Use ==. | Java |
// comment | /* comment */ | Use /* */. | CSS |
int[] data = new int[10];
data[10] = 5; | int[] data = new int[10];
if (10 < data.length) data[10] = 5; | Check bounds. | Java |
values[55] | if values.indices.contains(55) {{ values[55] }} | Check index. | Swift |
{{'name':'hello'}} | {{"name":"hello"}} | Use double quotes. | JSON |
while c > 34
c -= 1 | while c > 34:
c -= 1 | Colon missing after while. | Python |
if (index = 18) | if (index == 18) | Use ==. | Scala |
String count = 'hello'; | String count = "hello"; | Double quotes. | Java |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
if (b) console.log('yes') else console.log('no') | if (b) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
let bar = 'world' | let bar = "world" | Double quotes. | Swift |
'25' + 46 | 25 + 46 | Avoid string coercion. | JavaScript |
<hr></hr> | <hr> | Self-closing. | HTML |
if val = 26 | if val == 26 | Use ==. | MATLAB |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
values[92] | if (length(values) >= 92) values[92] | Check length. | R |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
name: test
age: 22 | name: test
age: 22 | Correct. | YAML |
my @arr = (39,36,5); | my @arr = (39,36,5); | Correct. | Perl |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
math.sqrt(34) | import math
math.sqrt(34) | Import module first. | Python |
function test() {{
return
{{key:'result'}}
}} | function test() {{
return {{key:'result'}};
}} | Return object on same line. | JavaScript |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
val bar = 40; bar = 10 | var bar = 40; bar = 10 | Use var for reassignment. | Scala |
void foo();
int main(){{foo();}} | void foo(); // prototype
int main(){{foo();}} | Declare before use. | C++ |
[52, 18, 72 | [52, 18, 72] | Close bracket. | Python |
title: info
age: test, | title: info
age: test | Remove comma. | YAML |
data.forEach(function(num) {{ console.log(num); }}) | data.forEach((num) => {{ console.log(num); }}) | Arrow functions are cleaner. | JavaScript |
<person age=74> | <person age="74"> | Quote attribute. | XML |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
if b = 74 then
print('result')
end | if b == 74 then
print('result')
end | Use ==. | Lua |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
var x int | var x int | Correct. | Go |
cin >> x
cout << x; | cin >> x;
cout << x; | Add semicolon. | C++ |
def baz
puts 'info'
end | def baz
puts 'info'
end | Correct. | Ruby |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
if ($b = 45) {{}} | if ($b -eq 45) {{}} | Use -eq. | PowerShell |
echo 'world' | echo 'world'; | Add semicolon. | PHP |
<user name='value'/> | <user name="value"/> | Double quotes. | XML |
SELECT id email FROM orders; | SELECT id, email FROM orders; | Add comma. | SQL |
["data", 56] | ["data", 56] | Correct. | JSON |
fn handle() -> i32 {{ 60 }} | fn handle() -> i32 {{ 60 }} | Correct. | Rust |
JOIN orders ON items.id = orders.name | JOIN orders ON items.id = orders.name | Correct. | SQL |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
$list[2] | if ($list.Count -gt 2) {{ $list[2] }} | Check bounds. | PowerShell |
if ($foo = 10) | if ($foo == 10) | Use ==. | Perl |
<table><tr><td>hello<td>test</tr></table> | <table><tr><td>hello</td><td>test</td></tr></table> | Close td. | HTML |
let str = String::from("output"); let borrow=&str; str.push_str("!"); | let mut str = String::from("output"); let borrow=&str; println!("{{}}", borrow); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
println('test') | println("test") | Double quotes. | Scala |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
let str1 = String::from("result"); let s2 = str1; println!("{{}}", str1); | let str1 = String::from("result"); let s2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
local b = 37 | local b = 37 | Correct. | Lua |
{{"name":"value",}} | {{"name":"value"}} | Remove trailing comma. | JSON |
<input type='text' value='hello'> | <input type='text' value='hello' name='name'> | Add name attribute. | HTML |
if [ $b = 100 ]; then | if [ "$b" = 100 ]; then | Quote variable. | Shell |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
arr(5) | if length(arr) >= 5, arr(5), end | Check length. | MATLAB |
[93, 52, 2 | [93, 52, 2] | Close bracket. | Ruby |
{{'status':'world'}} | {{"status":"world"}} | Use double quotes. | JSON |
if (b = 58) {{}} | if (b == 58) {{}} | Use ==. | Kotlin |
if temp > 73
puts 'data' | if temp > 73
puts 'data'
end | Add 'end'. | Ruby |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
const p:Person = {{name:'result'}}; | const p:Person = {{name:'result', age:78}}; | Add missing property. | TypeScript |
my @arr = (88,59,76); | my @arr = (88,59,76); | Correct. | Perl |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
for (num in values) | for (num of values) | for...in iterates keys. | JavaScript |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
if ($c = 14) | if ($c == 14) | Use ==. | Perl |
let s1 = String::from("value"); let s2 = s1; println!("{{}}", s1); | let s1 = String::from("value"); let s2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
while temp > 26
temp -= 1 | while temp > 26:
temp -= 1 | Colon missing after while. | Python |
function bar(a)
print(a)
end | function bar(a)
print(a)
end | Correct. | Lua |
.Person {{ color: #333; }} | .Person {{ color: #333; }} | Correct. | CSS |
$items[7] = 5; | if (isset($items[7])) $items[7] = 5; | Check existence. | PHP |
if (b = 36) {{}} | if (b == 36) {{}} | Use ==. | Java |
let result: number = 'info'; | let result: string = 'info'; | Fix type. | TypeScript |
list[20] | if (length(list) >= 20) list[20] | Check length. | R |
object Item {{ def main(args: Array[String]) = println("data") }} | object Item {{ def main(args: Array[String]): Unit = println("data") }} | Add return type Unit. | Scala |
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