wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
console.log('data' | console.log('data') | Close parenthesis. | JavaScript |
cin >> foo
cout << foo; | cin >> foo;
cout << foo; | Add semicolon. | C++ |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
void main() {{ print('value') }} | void main() {{ print('value'); }} | Add semicolon. | Dart |
{ "name": "message" } | { "name": "message" } | Correct. | JSON |
val y = 'value' | val y = "value" | Double quotes. | Kotlin |
[90, 3, 67 | [90, 3, 67] | Close bracket. | Ruby |
const x = 1; x = 84; | let x = 1; x = 84; | Cannot reassign const. | JavaScript |
const bar; | const bar = 88; | Initialize const. | JavaScript |
SELECT id email FROM orders; | SELECT id, email FROM orders; | Add comma. | SQL |
if x > 90
print('result') | if x > 90:
print('result') | Colon missing after if. | Python |
class User {{ int count; }}
obj.count=5; | class User {{ public int count; }}
obj.count=5; | Make field public. | Java |
def render
puts 'data'
end | def render
puts 'data'
end | Correct. | Ruby |
jwt.sign({{id:66}}, 'secret'); | jwt.sign({{id:66}}, 'secret', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
<hr></hr> | <hr> | Self-closing. | HTML |
if (b = 74) {{}} | if (b == 74) {{}} | Use ==. | Kotlin |
switch(val){{ case 60: break; }} | switch(val){{ case 60: break; default: break; }} | Add default case. | Java |
let count = 'message' | let count = "message" | Double quotes. | Swift |
var x = 58; | var x = 58; | Correct. | Dart |
let y = 66; let y = 21; | let y = 66; y = 21; | Duplicate declaration. | JavaScript |
{{'status':'test'}} | {{"status":"test"}} | Use double quotes. | JSON |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
data[1] | if (data.indices.contains(1)) data[1] | Check index. | Kotlin |
'data' + 72 | 'data' + str(72) | Can't add int to string. | Python |
<div><p>info</div></p> | <div><p>info</p></div> | Nest properly. | HTML |
val val: Int = 'info' | val val: String = 'info' | Fix type. | Kotlin |
def process(y):
return y + 1 | def process(y):
return y + 1 | Correct. | Python |
var x int | var x int | Correct. | Go |
const obj:Person = {{name:'output'}}; | const obj:Person = {{name:'output', age:7}}; | Add missing property. | TypeScript |
data(30) | if length(data) >= 30, data(30), end | Check length. | MATLAB |
function process(result)
print(result)
end | function process(result)
print(result)
end | Correct. | Lua |
$val = 19; if ($val = 19) {{}} | $val = 19; if ($val == 19) {{}} | Use ==. | PHP |
items[33] | if (length(items) >= 33) items[33] | Check length. | R |
int[] arr = new int[34];
arr[34] = 5; | int[] arr = new int[34];
if (34 < arr.length) arr[34] = 5; | Check bounds. | Java |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
String y = 'info'; | String y = "info"; | Double quotes. | Java |
fmt.Println 'data' | fmt.Println('data') | Missing parentheses. | Go |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
h1 {{ font-size:20px color:red; }} | h1 {{ font-size:20px; color:red; }} | Add semicolon. | CSS |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
random.sqrt(89) | import random
random.sqrt(89) | Import module first. | Python |
Write-Host 'info' | Write-Host 'info' | Correct. | PowerShell |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
for (temp in arr) | for (temp of arr) | for...in iterates keys. | JavaScript |
<person age=45> | <person age="45"> | Quote attribute. | XML |
int values[28]; values[28]=5; | int values[28]; if(28<28){{}} else values[28]=5; | Bounds check. | C++ |
echo hello test | echo 'hello test' | Quote to prevent splitting. | Shell |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
val num = 23; num = 36 | var num = 23; num = 36 | Use var for reassignment. | Scala |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
for foo in range(2)
print(foo) | for foo in range(2):
print(foo) | Colon after for. | Python |
bar = 84 | bar=84 | No spaces. | Shell |
if (y = 3) {} | if (y == 3) {} | Use ==. | Dart |
class = 'output' | class_name = 'output' | 'class' is a keyword. | Python |
if foo = 65 | if foo == 65 | Use ==. | Ruby |
local item = 3 | local item = 3 | Correct. | Lua |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
let data: number = 'output'; | let data: string = 'output'; | Fix type. | TypeScript |
print('world') | print('world') | Correct. | R |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
arr.forEach(function(index) {{ console.log(index); }}) | arr.forEach((index) => {{ console.log(index); }}) | Arrow functions are cleaner. | JavaScript |
if (result = 90) | if (result == 90) | Use ==. | Scala |
if [ $c = 53 ]; then | if [ "$c" = 53 ]; then | Quote variable. | Shell |
if (item = 29) {{}} | if (item === 29) {{}} | Use === for equality. | JavaScript |
int c = 'info'; | String c = 'info'; | Type mismatch. | Dart |
var y int = 'world' | var y string = 'world' | Type mismatch. | Go |
function compute() {{ echo 'output'; }} | function compute() {{ echo 'output'; }} | Correct. | PHP |
object Person {{ def main(args: Array[String]) = println("test") }} | object Person {{ def main(args: Array[String]): Unit = println("test") }} | Add return type Unit. | Scala |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
println('data') | println("data") | Double quotes. | Scala |
List(84,69,26) | List(84,69,26) | Correct. | Scala |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
'64' + 4 | 64 + 4 | Avoid string coercion. | JavaScript |
["hello", 62] | ["hello", 62] | Correct. | JSON |
a > 12 & z < 100 | a > 12 and z < 100 | Use 'and' not '&'. | Python |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
if (num = 4) | if (num == 4) | Use ==. | R |
name: data
age: 95 | name: data
age: 95 | Correct. | YAML |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
yield x | yield x | Correct yield. | Python |
function render(bar:string){{return bar;}} render(14); | function render(bar:string){{return bar;}} render('data'); | Pass correct type. | TypeScript |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
[36, 36, 86 | [36, 36, 86] | Close bracket. | Python |
let val = 6; val += 1; | let mut val = 6; val += 1; | Need mut to modify. | Rust |
let b: Int = 'test' | let b: String = 'test' | Fix type. | Swift |
with open('data.txt') as fh:
data = fh.read() | with open('data.txt') as fh:
data = fh.read() | Correct. | Python |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
z > 36 & z < 38 | z > 36 and z < 38 | Use 'and' not '&'. | Python |
cin >> c; | int c;
cin >> c; | Declare variable. | C++ |
val val = 'value' | val val = "value" | Double quotes. | Kotlin |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
System.out.println('output') | System.out.println('output'); | Add semicolon. | Java |
let a: i32 = "value"; | let a: &str = "value"; | Type mismatch. | Rust |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
cin >> index
cout << index; | cin >> index;
cout << index; | Add semicolon. | C++ |
class Order {{ int x; }}
obj.x=5; | class Order {{ public int x; }}
obj.x=5; | Make field public. | Java |
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