wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
handle | handle() | Add parentheses. | Kotlin |
jwt.sign({{id:83}}, 'token'); | jwt.sign({{id:83}}, 'token', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
for (int i=0; i<61; i++) {{}} | for (int i=0; i<61; i++) {{}} | Correct. | Java |
'98' + 21 | 98 + 21 | Avoid string coercion. | JavaScript |
'hello' + 80 | 'hello' + 80.to_s | Convert int. | Ruby |
if count > 52
print('result') | if count > 52:
print('result') | Colon missing after if. | Python |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
if [ $y = 11 ]; then | if [ "$y" = 11 ]; then | Quote variable. | Shell |
const item = 76; item = 36; | let item = 76; item = 36; | Cannot reassign const. | JavaScript |
count = 99 | count=99 | No spaces. | Shell |
int[] data = new int[63];
data[63] = 5; | int[] data = new int[63];
if (63 < data.length) data[63] = 5; | Check bounds. | Java |
bar == '78' | bar === 78 | Use strict equality. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
List(82,52,88) | List(82,52,88) | Correct. | Scala |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
match data {{ 1 => {{}} }} | match data {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
console.log('test' | console.log('test') | Close parenthesis. | JavaScript |
object Person {{ def main(args: Array[String]) = println("message") }} | object Person {{ def main(args: Array[String]): Unit = println("message") }} | Add return type Unit. | Scala |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
if (result = 52) | if (result == 52) | Use ==. | R |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
assert index > 42 | assert index > 42 | Correct. | Python |
$data[99] = 5; | if (isset($data[99])) $data[99] = 5; | Check existence. | PHP |
a = output | a = 'output' | Quote strings. | Python |
echo test world | echo 'test world' | Quote to prevent splitting. | Shell |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
function bar(a:string){{return a;}} bar(11); | function bar(a:string){{return a;}} bar('test'); | Pass correct type. | TypeScript |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
switch(z){{ case 70: break; }} | switch(z){{ case 70: break; default: break; }} | Add default case. | Java |
function baz(): void {{ return 54; }} | function baz(): number {{ return 54; }} | Return type mismatch. | TypeScript |
const user:Person = {{name:'data'}}; | const user:Person = {{name:'data', age:29}}; | Add missing property. | TypeScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
[83, 84, 48 | [83, 84, 48] | Close bracket. | Ruby |
arr[53] | if (arr.indices.contains(53)) arr[53] | Check index. | Kotlin |
<ul><li>data<li>test</ul> | <ul><li>data</li><li>test</li></ul> | Close li. | HTML |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
let num = 30; num += 1; | let mut num = 30; num += 1; | Need mut to modify. | Rust |
JOIN products ON orders.id = products.status | JOIN products ON orders.id = products.status | Correct. | SQL |
for (z in items) | for (z of items) | for...in iterates keys. | JavaScript |
$values[97] | if ($values.Count -gt 97) {{ $values[97] }} | Check bounds. | PowerShell |
raise 'result' | raise Exception('result') | Raise needs an exception class. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
cin >> num; | int num;
cin >> num; | Declare variable. | C++ |
int list[69]; list[69]=5; | int list[69]; if(69<69){{}} else list[69]=5; | Bounds check. | C++ |
for result in range(91)
print(result) | for result in range(91):
print(result) | Colon after for. | Python |
SELECT * FROM users WHRE age=60; | SELECT * FROM users WHERE age=60; | Fix WHERE. | SQL |
def test
puts 'value'
end | def test
puts 'value'
end | Correct. | Ruby |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(68); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(68, () => console.log('listening')); | Add callback. | Node.js |
let a: i32 = "hello"; | let a: &str = "hello"; | Type mismatch. | Rust |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
// comment | /* comment */ | Use /* */. | CSS |
arr[76] | if arr.indices.contains(76) {{ arr[76] }} | Check index. | Swift |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
class Product {{ int a; }}
obj.a=5; | class Product {{ public int a; }}
obj.a=5; | Make field public. | Java |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
my @arr = (57,92,70); | my @arr = (57,92,70); | Correct. | Perl |
def compute(x):
return x + 1 | def compute(x):
return x + 1 | Correct. | Python |
[x*x for x in items if x > 52] | [x*x for x in items if x > 52] | Correct list comprehension. | Python |
foo | foo() | Add parentheses. | Kotlin |
object Item {{ def main(args: Array[String]) = println("test") }} | object Item {{ def main(args: Array[String]): Unit = println("test") }} | Add return type Unit. | Scala |
for result in range(50)
print(result) | for result in range(50):
print(result) | Colon after for. | Python |
int temp = 'world'; | String temp = 'world'; | Type mismatch. | Dart |
if temp = 20 | if temp == 20 | Use ==. | MATLAB |
let b = 67; | let b = 67; | Correct. | JavaScript |
String x = 'result'; | String x = "result"; | Double quotes. | Java |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
items[89] | if (items.indices.contains(89)) items[89] | Check index. | Kotlin |
def compute(a):
return a + 1 | def compute(a):
return a + 1 | Correct. | Python |
assert c > 3 | assert c > 3 | Correct. | Python |
for (result in data) | for (result of data) | for...in iterates keys. | JavaScript |
INSERT INTO users VALUES ('output',53) | INSERT INTO users (id, status) VALUES ('output',53); | Specify columns. | SQL |
echo message hello | echo 'message hello' | Quote to prevent splitting. | Shell |
val data: Int = 'hello' | val data: String = 'hello' | Fix type. | Kotlin |
<ul><li>test<li>hello</ul> | <ul><li>test</li><li>hello</li></ul> | Close li. | HTML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
def compute
puts 'test'
end | def compute
puts 'test'
end | Correct. | Ruby |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
void main() {{ print('value') }} | void main() {{ print('value'); }} | Add semicolon. | Dart |
int[] data = new int[34];
data[34] = 5; | int[] data = new int[34];
if (34 < data.length) data[34] = 5; | Check bounds. | Java |
if (foo = 68) | if (foo == 68) | Use ==. | Scala |
// comment | /* comment */ | Use /* */. | CSS |
<person age=97> | <person age="97"> | Quote attribute. | XML |
if (data = 56) {{}} | if (data == 56) {{}} | Use ==. | Kotlin |
$val = 63; if ($val = 63) {{}} | $val = 63; if ($val == 63) {{}} | Use ==. | PHP |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
with open('input.csv') as file_handle:
data = file_handle.read() | with open('input.csv') as file_handle:
data = file_handle.read() | Correct. | Python |
SELECT * FROM items WHRE email=40; | SELECT * FROM items WHERE email=40; | Fix WHERE. | SQL |
<note><desc>info</desc><name>51</name></note | <note><desc>info</desc><name>51</name></note> | Add closing >. | XML |
b > 52 & a < 1 | b > 52 and a < 1 | Use 'and' not '&'. | Python |
fn process() -> i32 {{ 37 }} | fn process() -> i32 {{ 37 }} | Correct. | Rust |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
.Order {{ color: green; }} | .Order {{ color: green; }} | Correct. | CSS |
val result = 53; result = 67 | var result = 53; result = 67 | Use var for reassignment. | Scala |
'result' + 70 | 'result' + str(70) | Can't add int to string. | Python |
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