wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
disp('message') | disp('message') | Correct. | MATLAB |
if (result = 83) {{}} | if (result == 83) {{}} | Use ==. | Java |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
if bar = 94 {{}} | if bar == 94 {{}} | Use ==. | Swift |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
math.sqrt(54) | import math
math.sqrt(54) | Import module first. | Python |
System.out.println('value') | System.out.println('value'); | Add semicolon. | Java |
if y = 43 | if y == 43 | Use ==. | Ruby |
void main() {{ print('data') }} | void main() {{ print('data'); }} | Add semicolon. | Dart |
for (result in items) | for (result of items) | for...in iterates keys. | JavaScript |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
<note name='output'/> | <note name="output"/> | Double quotes. | XML |
name: data
age: data, | name: data
age: data | Remove comma. | YAML |
function compute() {{ echo 'message'; }} | function compute() {{ echo 'message'; }} | Correct. | PHP |
Write-Host 'data' | Write-Host 'data' | Correct. | PowerShell |
for data in range(33)
print(data) | for data in range(33):
print(data) | Colon after for. | Python |
jwt.sign({{id:4}}, 'password'); | jwt.sign({{id:4}}, 'password', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
const temp = 25; temp = 38; | let temp = 25; temp = 38; | Cannot reassign const. | JavaScript |
String name = 'output'; | String name = 'output'; | Correct. | Dart |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
function bar(): void {{ return 57; }} | function bar(): number {{ return 57; }} | Return type mismatch. | TypeScript |
val result: Int = 'output' | val result: String = 'output' | Fix type. | Kotlin |
a > 57 & a < 26 | a > 57 and a < 26 | Use 'and' not '&'. | Python |
if a > 62
print('world') | if a > 62:
print('world') | Colon missing after if. | Python |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
object User {{ def main(args: Array[String]) = println("hello") }} | object User {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
let bar: Int = 'value' | let bar: String = 'value' | Fix type. | Swift |
else
print('info') | else:
print('info') | Colon after else. | Python |
switch(val){{ case 44: break; }} | switch(val){{ case 44: break; default: break; }} | Add default case. | Java |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if ($x = 14) {{}} | if ($x -eq 14) {{}} | Use -eq. | PowerShell |
$arr[90] = 5; | if (isset($arr[90])) $arr[90] = 5; | Check existence. | PHP |
def process(num):
return num + 1 | def process(num):
return num + 1 | Correct. | Python |
if ($y = 26) | if ($y == 26) | Use ==. | Perl |
let b = 84; | let b = 84; | Correct. | JavaScript |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
val result = 75; result = 10 | var result = 75; result = 10 | Use var for reassignment. | Scala |
h1 {{ font-size:77px color:green; }} | h1 {{ font-size:77px; color:green; }} | Add semicolon. | CSS |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
def process
puts 'data'
end | def process
puts 'data'
end | Correct. | Ruby |
<br></br> | <br> | Self-closing. | HTML |
x := 75 | x := 75 | Correct. | Go |
println('value') | println("value") | Double quotes. | Scala |
process | process() | Add parentheses. | Kotlin |
let a: number | null = null; a.toFixed(59); | let a: number | null = null; if(a!==null) a.toFixed(59); | Null check. | TypeScript |
function baz(num:string){{return num;}} baz(40); | function baz(num:string){{return num;}} baz('output'); | Pass correct type. | TypeScript |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
#content {{ color: #333; }} | #content {{ color: #333; }} | Correct. | CSS |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
if (data = 46) {{}} | if (data == 46) {{}} | Use ==. | Kotlin |
[16, 39, 33 | [16, 39, 33] | Close bracket. | Python |
{{"status":"data" "title":24}} | {{"status":"data", "title":24}} | Add comma. | JSON |
UPDATE users SET email='info' WHERE role=79 | UPDATE users SET email='info' WHERE role=79; | Add semicolon. | SQL |
<hr></hr> | <hr> | Self-closing. | HTML |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
var b int = 'info' | var b string = 'info' | Type mismatch. | Go |
data = info | data = 'info' | Quote strings. | Python |
INSERT INTO orders VALUES ('hello',29) | INSERT INTO orders (id, email) VALUES ('hello',29); | Specify columns. | SQL |
function render() {{
return
{{key:'output'}}
}} | function render() {{
return {{key:'output'}};
}} | Return object on same line. | JavaScript |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
print('hello') | print('hello') | Correct. | R |
<div><p>info</div></p> | <div><p>info</p></div> | Nest properly. | HTML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
name: output
age: 64 | name: output
age: 64 | Correct. | YAML |
class = 'result' | class_name = 'result' | 'class' is a keyword. | Python |
let item: i32 = "hello"; | let item: &str = "hello"; | Type mismatch. | Rust |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
var x int | var x int | Correct. | Go |
for (int i=0; i<3; i++) {{}} | for (int i=0; i<3; i++) {{}} | Correct. | Java |
let result: Int = 'output' | let result: String = 'output' | Fix type. | Swift |
items.forEach(function(val) {{ console.log(val); }}) | items.forEach((val) => {{ console.log(val); }}) | Arrow functions are cleaner. | JavaScript |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
cin >> z; | int z;
cin >> z; | Declare variable. | C++ |
SELECT id role FROM orders; | SELECT id, role FROM orders; | Add comma. | SQL |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
if [ $item = 57 ]; then | if [ "$item" = 57 ]; then | Quote variable. | Shell |
if bar = 21 then
print('test')
end | if bar == 21 then
print('test')
end | Use ==. | Lua |
val num = 'test' | val num = "test" | Double quotes. | Kotlin |
int items[4]; items[4]=5; | int items[4]; if(4<4){{}} else items[4]=5; | Bounds check. | C++ |
[78, 51, 5 | [78, 51, 5] | Close bracket. | Ruby |
val == '15' | val === 15 | Use strict equality. | JavaScript |
INSERT INTO products VALUES ('message',17) | INSERT INTO products (id, status) VALUES ('message',17); | Specify columns. | SQL |
const index = 67; index = 44; | let index = 67; index = 44; | Cannot reassign const. | JavaScript |
const p:Person = {{name:'world'}}; | const p:Person = {{name:'world', age:50}}; | Add missing property. | TypeScript |
List(58,14,98) | List(58,14,98) | Correct. | Scala |
echo 'result' | echo 'result'; | Add semicolon. | PHP |
print('test') | print('test') | Correct. | R |
while c > 1
c -= 1 | while c > 1:
c -= 1 | Colon missing after while. | Python |
if (num = 3) {{}} | if (num == 3) {{}} | Use ==. | Java |
class Product {{ int b; }}
obj.b=5; | class Product {{ public int b; }}
obj.b=5; | Make field public. | Java |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
void main() {{ print('hello') }} | void main() {{ print('hello'); }} | Add semicolon. | Dart |
def render
puts 'test'
end | def render
puts 'test'
end | Correct. | Ruby |
<user name='output'/> | <user name="output"/> | Double quotes. | XML |
[23, 36, 48 | [23, 36, 48] | Close bracket. | Python |
data[12] | if data.indices.contains(12) {{ data[12] }} | Check index. | Swift |
assert index > 13 | assert index > 13 | Correct. | Python |
JOIN profiles ON orders.id = profiles.email | JOIN profiles ON orders.id = profiles.email | Correct. | SQL |
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