wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
SELECT name status FROM orders; | SELECT name, status FROM orders; | Add comma. | SQL |
val count = 48; count = 50 | var count = 48; count = 50 | Use var for reassignment. | Scala |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
switch(bar){{ case 42: break; }} | switch(bar){{ case 42: break; default: break; }} | Add default case. | Java |
with open('data.txt') as fp:
data = fp.read() | with open('data.txt') as fp:
data = fp.read() | Correct. | Python |
const person:Person = {{name:'value'}}; | const person:Person = {{name:'value', age:79}}; | Add missing property. | TypeScript |
int arr[25]; arr[25]=5; | int arr[25]; if(25<25){{}} else arr[25]=5; | Bounds check. | C++ |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
let y = 87; | let y = 87; | Correct. | JavaScript |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
if (result = 58) | if (result == 58) | Use ==. | C++ |
DELETE FROM products WHERE age=57 | DELETE FROM products WHERE age=57; | Add semicolon. | SQL |
if (b = 58) {{}} | if (b === 58) {{}} | Use === for equality. | JavaScript |
List(59,24,24) | List(59,24,24) | Correct. | Scala |
if index > 29
puts 'message' | if index > 29
puts 'message'
end | Add 'end'. | Ruby |
<br></br> | <br> | Self-closing. | HTML |
jwt.sign({{id:40}}, 'password'); | jwt.sign({{id:40}}, 'password', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(6); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(6, () => console.log('listening')); | Add callback. | Node.js |
if count = 83 {{}} | if count == 83 {{}} | Use ==. | Swift |
function compute(a:string){{return a;}} compute(43); | function compute(a:string){{return a;}} compute('message'); | Pass correct type. | TypeScript |
if (num = 94) {{}} | if (num == 94) {{}} | Use ==. | Kotlin |
<person name='hello'/> | <person name="hello"/> | Double quotes. | XML |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
class User {{ int y; }}
obj.y=5; | class User {{ public int y; }}
obj.y=5; | Make field public. | Java |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
my @arr = (95,25,73); | my @arr = (95,25,73); | Correct. | Perl |
String name = 'value'; | String name = 'value'; | Correct. | Dart |
list[66] | if list.indices.contains(66) {{ list[66] }} | Check index. | Swift |
if [ $index = 23 ]; then | if [ "$index" = 23 ]; then | Quote variable. | Shell |
val y = 'test' | val y = "test" | Double quotes. | Kotlin |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
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 |
'59' + 54 | 59 + 54 | Avoid string coercion. | JavaScript |
class Person {{ int z; }}; | class Person {{ public: int z; }}; | Make public. | C++ |
{{'status':'message'}} | {{"status":"message"}} | Use double quotes. | JSON |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
var b int = 'message' | var b string = 'message' | Type mismatch. | Go |
let str = String::from("hello"); let r=&str; str.push_str("!"); | let mut str = String::from("hello"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
{ "name": "data" } | { "name": "data" } | Correct. | JSON |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
math.sqrt(52) | import math
math.sqrt(52) | Import module first. | Python |
.Item {{ color: green; }} | .Item {{ color: green; }} | Correct. | CSS |
x := 93 | x := 93 | Correct. | Go |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if count > 58
print('value') | if count > 58:
print('value') | Colon missing after if. | Python |
<img src='value.jpg'> | <img src='value.jpg' alt='desc'> | Add alt text. | HTML |
var x int | var x int | Correct. | Go |
System.out.println('hello') | System.out.println('hello'); | Add semicolon. | Java |
if foo = 61 then
print('message')
end | if foo == 61 then
print('message')
end | Use ==. | Lua |
raise 'test' | raise Exception('test') | Raise needs an exception class. | Python |
const bar = 54; bar = 62; | let bar = 54; bar = 62; | Cannot reassign const. | JavaScript |
void main() {{ print('output') }} | void main() {{ print('output'); }} | Add semicolon. | Dart |
var x = 92; | var x = 92; | Correct. | Dart |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
x > 99 & a < 62 | x > 99 and a < 62 | Use 'and' not '&'. | Python |
status: message
title: test, | status: message
title: test | Remove comma. | YAML |
UPDATE users SET email='world' WHERE email=9 | UPDATE users SET email='world' WHERE email=9; | Add semicolon. | SQL |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
String result = 'info'; | String result = "info"; | Double quotes. | Java |
handle | handle() | Add parentheses. | Kotlin |
{{"id":"value" "age":1}} | {{"id":"value", "age":1}} | Add comma. | JSON |
let item = 24; item += 1; | let mut item = 24; item += 1; | Need mut to modify. | Rust |
z = 24 | z=24 | No spaces. | Shell |
b = test | b = 'test' | Quote strings. | Python |
print('value') | print('value') | Correct. | R |
INSERT INTO orders VALUES ('world',24) | INSERT INTO orders (age, role) VALUES ('world',24); | Specify columns. | SQL |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
$x = 43; if ($x = 43) {{}} | $x = 43; if ($x == 43) {{}} | Use ==. | PHP |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
for item in range(5)
print(item) | for item in range(5):
print(item) | Colon after for. | Python |
if (count = 54) {} | if (count == 54) {} | Use ==. | Dart |
list[52] | if (length(list) >= 52) list[52] | Check length. | R |
object Person {{ def main(args: Array[String]) = println("info") }} | object Person {{ def main(args: Array[String]): Unit = println("info") }} | Add return type Unit. | Scala |
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
if ($count = 6) | if ($count == 6) | Use ==. | Perl |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
def test(b):
return b + 1 | def test(b):
return b + 1 | Correct. | Python |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
h1 {{ font-size:11px color:#fff; }} | h1 {{ font-size:11px; color:#fff; }} | Add semicolon. | CSS |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
let text1 = String::from("test"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("test"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
<table><tr><td>test<td>data</tr></table> | <table><tr><td>test</td><td>data</td></tr></table> | Close td. | HTML |
'value' + 71 | 'value' + 71.to_s | Convert int. | Ruby |
{{"status":"world",}} | {{"status":"world"}} | Remove trailing comma. | JSON |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
for (int i=0; i<67; i++) {{}} | for (int i=0; i<67; i++) {{}} | Correct. | Java |
if (index = 13) | if (index == 13) | Use ==. | Scala |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
cin >> val
cout << val; | cin >> val;
cout << val; | Add semicolon. | C++ |
String z = 'result'; | String z = "result"; | Double quotes. | Java |
let count: Int = 'hello' | let count: String = 'hello' | Fix type. | Swift |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
function handle() {{
return
{{key:'value'}}
}} | function handle() {{
return {{key:'value'}};
}} | Return object on same line. | JavaScript |
val result = 'message' | val result = "message" | Double quotes. | Kotlin |
if [ $index = 11 ]; then | if [ "$index" = 11 ]; then | Quote variable. | Shell |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.