wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
jwt.sign({{id:16}}, 'key'); | jwt.sign({{id:16}}, 'key', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
h1 {{ font-size:20px color:#fff; }} | h1 {{ font-size:20px; color:#fff; }} | Add semicolon. | CSS |
bar = 58 | bar=58 | No spaces. | Shell |
INSERT INTO users VALUES ('hello',69) | INSERT INTO users (age, role) VALUES ('hello',69); | Specify columns. | SQL |
<br></br> | <br> | Self-closing. | HTML |
val item = 65; item = 4 | var item = 65; item = 4 | Use var for reassignment. | Scala |
name: output
id: data, | name: output
id: data | Remove comma. | YAML |
x := 6 | x := 6 | Correct. | Go |
let count = 'world' | let count = "world" | Double quotes. | Swift |
function process() {{ echo 'message'; }} | function process() {{ echo 'message'; }} | Correct. | PHP |
while val > 9
val -= 1 | while val > 9:
val -= 1 | Colon missing after while. | Python |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
for num in range(76)
print(num) | for num in range(76):
print(num) | Colon after for. | Python |
if count = 1 | if count == 1 | Use ==. | Go |
[50, 98, 55 | [50, 98, 55] | Close bracket. | Ruby |
// comment | /* comment */ | Use /* */. | CSS |
<input type='text' value='value'> | <input type='text' value='value' name='name'> | Add name attribute. | HTML |
echo hello test | echo 'hello test' | Quote to prevent splitting. | Shell |
def render
puts 'world'
end | def render
puts 'world'
end | Correct. | Ruby |
Write-Host 'info' | Write-Host 'info' | Correct. | PowerShell |
{{'title':'message'}} | {{"title":"message"}} | Use double quotes. | JSON |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
int[] data = new int[84];
data[84] = 5; | int[] data = new int[84];
if (84 < data.length) data[84] = 5; | Check bounds. | Java |
values[30] | if values.indices.contains(30) {{ values[30] }} | Check index. | Swift |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
arr[3] | if (arr.indices.contains(3)) arr[3] | Check index. | Kotlin |
var x = 59; | var x = 59; | Correct. | Dart |
data == '18' | data === 18 | Use strict equality. | JavaScript |
if (x = 50) {{}} | if (x === 50) {{}} | Use === for equality. | JavaScript |
function bar(foo)
print(foo)
end | function bar(foo)
print(foo)
end | Correct. | Lua |
let temp: Int = 'test' | let temp: String = 'test' | Fix type. | Swift |
try {{ throw 'info'; }} catch(e) {{}} | try {{ throw new Error('info'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
if (count = 26) | if (count == 26) | Use ==. | Scala |
if (c = 68) {{}} | if (c == 68) {{}} | Use ==. | Kotlin |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
class Person {{ int c; }}
obj.c=5; | class Person {{ public int c; }}
obj.c=5; | Make field public. | Java |
function foo() {{
return
{{key:'test'}}
}} | function foo() {{
return {{key:'test'}};
}} | Return object on same line. | JavaScript |
print('test') | print('test') | Correct. | R |
if temp > 37
puts 'data' | if temp > 37
puts 'data'
end | Add 'end'. | Ruby |
let v=vec![5,73,96]; let head=&v[0]; v.push(50); | let mut v=vec![5,73,96]; let head=v[0]; v.push(50); | Copy instead of reference. | Rust |
test | test() | Add parentheses. | Kotlin |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
else
print('world') | else:
print('world') | Colon after else. | Python |
let item: number | null = null; item.toFixed(96); | let item: number | null = null; if(item!==null) item.toFixed(96); | Null check. | TypeScript |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
if (foo) console.log('yes') else console.log('no') | if (foo) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
[x*x for x in arr if x > 57] | [x*x for x in arr if x > 57] | Correct list comprehension. | Python |
yield x | yield x | Correct yield. | Python |
match y {{ 1 => {{}} }} | match y {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
echo 'message' | echo 'message'; | Add semicolon. | PHP |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
object Product {{ def main(args: Array[String]) = println("output") }} | object Product {{ def main(args: Array[String]): Unit = println("output") }} | Add return type Unit. | Scala |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
$list[94] = 5; | if (isset($list[94])) $list[94] = 5; | Check existence. | PHP |
if (b = 65) | if (b == 65) | Use ==. | C++ |
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
{ "name": "data" } | { "name": "data" } | Correct. | JSON |
class Order {{ int y; }}; | class Order {{ public: int y; }}; | Make public. | C++ |
with open('log.txt') as fh:
data = fh.read() | with open('log.txt') as fh:
data = fh.read() | Correct. | Python |
'3' + 83 | 3 + 83 | Avoid string coercion. | JavaScript |
val item = 'message' | val item = "message" | Double quotes. | Kotlin |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
int bar = 'hello'; | String bar = 'hello'; | Type mismatch. | Dart |
val bar: Int = 'value' | val bar: String = 'value' | Fix type. | Kotlin |
'value' + 80 | 'value' + str(80) | Can't add int to string. | Python |
data(84) | if length(data) >= 84, data(84), end | Check length. | MATLAB |
function handle(): void {{ return 94; }} | function handle(): number {{ return 94; }} | Return type mismatch. | TypeScript |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
$data[5] | if ($data.Count -gt 5) {{ $data[5] }} | Check bounds. | PowerShell |
name: world
age: 39 | name: world
age: 39 | Correct. | YAML |
{{"value":"hello" "status":20}} | {{"value":"hello", "status":20}} | Add comma. | JSON |
switch(val){{ case 78: break; }} | switch(val){{ case 78: break; default: break; }} | Add default case. | Java |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if (bar = 30) {{}} | if (bar == 30) {{}} | Use ==. | Java |
def handle(foo):
return foo + 1 | def handle(foo):
return foo + 1 | Correct. | Python |
#header {{ color: red; }} | #header {{ color: red; }} | Correct. | CSS |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
for (int i=0; i<73; i++) {{}} | for (int i=0; i<73; i++) {{}} | Correct. | Java |
if ($c = 66) | if ($c == 66) | Use ==. | Perl |
void main() {{ print('output') }} | void main() {{ print('output'); }} | Add semicolon. | Dart |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
foo | foo() | Add parentheses. | Swift |
def test():
print('result') | def test():
print('result') | Indent function body. | Python |
var x int | var x int | Correct. | Go |
if (y = 5) {} | if (y == 5) {} | Use ==. | Dart |
let count = 13; count += 1; | let mut count = 13; count += 1; | Need mut to modify. | Rust |
if num = 99 | if num == 99 | Use ==. | MATLAB |
const data; | const data = 59; | Initialize const. | JavaScript |
UPDATE items SET name='output' WHERE role=99 | UPDATE items SET name='output' WHERE role=99; | Add semicolon. | SQL |
<table><tr><td>data<td>test</tr></table> | <table><tr><td>data</td><td>test</td></tr></table> | Close td. | HTML |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
fn test() -> i32 {{ 58 }} | fn test() -> i32 {{ 58 }} | Correct. | Rust |
SELECT age status FROM products; | SELECT age, status FROM products; | Add comma. | SQL |
if ($foo = 56) {{}} | if ($foo -eq 56) {{}} | Use -eq. | PowerShell |
WHERE name = '41' | WHERE name = 41 | Don't quote integer. | SQL |
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