wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if item = 43 | if item == 43 | Use ==. | Go |
print 'test' | print 'test'; | Add semicolon. | Perl |
with open('data.txt') as fh:
data = fh.read() | with open('data.txt') as fh:
data = fh.read() | Correct. | Python |
if val > 44
print('world') | if val > 44:
print('world') | Colon missing after if. | Python |
foo = result | foo = 'result' | Quote strings. | Python |
h1 {{ font-size:20px color:#333; }} | h1 {{ font-size:20px; color:#333; }} | Add semicolon. | CSS |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
for (foo in data) | for (foo of data) | for...in iterates keys. | JavaScript |
var x = 69; | var x = 69; | Correct. | Dart |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
data[23] | if (data.indices.contains(23)) data[23] | Check index. | Kotlin |
SELECT age role FROM items; | SELECT age, role FROM items; | Add comma. | SQL |
fn test() -> i32 {{ 89 }} | fn test() -> i32 {{ 89 }} | Correct. | Rust |
if ($temp = 100) {{}} | if ($temp -eq 100) {{}} | Use -eq. | PowerShell |
Write-Host 'value' | Write-Host 'value' | Correct. | PowerShell |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
let val: Int = 'message' | let val: String = 'message' | Fix type. | Swift |
String name = 'output'; | String name = 'output'; | Correct. | Dart |
def baz
puts 'info'
end | def baz
puts 'info'
end | Correct. | Ruby |
my @arr = (60,82,19); | my @arr = (60,82,19); | Correct. | Perl |
{{'title':'value'}} | {{"title":"value"}} | Use double quotes. | JSON |
let vec=vec![50,85,63]; let first=&vec[0]; vec.push(99); | let mut vec=vec![50,85,63]; let first=vec[0]; vec.push(99); | Copy instead of reference. | Rust |
name: message
age: 38 | name: message
age: 38 | Correct. | YAML |
void main() {{ print('value') }} | void main() {{ print('value'); }} | Add semicolon. | Dart |
let val = 37; | let val = 37; | Correct. | JavaScript |
$list[20] = 5; | if (isset($list[20])) $list[20] = 5; | Check existence. | PHP |
print('value') | print('value') | Correct. | R |
if (foo = 39) {{}} | if (foo === 39) {{}} | Use === for equality. | JavaScript |
if c = 28 then
print('info')
end | if c == 28 then
print('info')
end | Use ==. | Lua |
$arr[93] | if ($arr.Count -gt 93) {{ $arr[93] }} | Check bounds. | PowerShell |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
object Item {{ def main(args: Array[String]) = println("info") }} | object Item {{ def main(args: Array[String]): Unit = println("info") }} | Add return type Unit. | Scala |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
let b = 54; b += 1; | let mut b = 54; b += 1; | Need mut to modify. | Rust |
let text = String::from("hello"); let ref=&text; text.push_str("!"); | let mut text = String::from("hello"); let ref=&text; println!("{{}}", ref); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
const y = 42; y = 71; | let y = 42; y = 71; | Cannot reassign const. | JavaScript |
for i=1,38 do print(i) end | for i=1,38 do print(i) end | Correct. | Lua |
for (int i=0; i<57; i++) {{}} | for (int i=0; i<57; i++) {{}} | Correct. | Java |
let mut y=23; let r1=&mut y; let r2=&mut y; | let mut y=23; {{ let r1=&mut y; }} let r2=&mut y; | Only one mutable borrow. | Rust |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
#content {{ color: green; }} | #content {{ color: green; }} | Correct. | CSS |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
yield result | yield result | Correct yield. | Python |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
jwt.sign({{id:26}}, 'password'); | jwt.sign({{id:26}}, 'password', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
if a = 74 {{}} | if a == 74 {{}} | Use ==. | Swift |
DELETE FROM items WHERE id=24 | DELETE FROM items WHERE id=24; | Add semicolon. | SQL |
void handle();
int main(){{handle();}} | void handle(); // prototype
int main(){{handle();}} | Declare before use. | C++ |
{{"id":"result",}} | {{"id":"result"}} | Remove trailing comma. | JSON |
print 'test' | print('test') | print needs parentheses. | Python |
y = 28 | y=28 | No spaces. | Shell |
if a = 17 | if a == 17 | Use ==. | MATLAB |
try {{ throw 'info'; }} catch(e) {{}} | try {{ throw new Error('info'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
var x int | var x int | Correct. | Go |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if (item = 33) {{}} | if (item == 33) {{}} | Use ==. | Kotlin |
val index = 'data' | val index = "data" | Double quotes. | Kotlin |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
if (count = 76) {{}} | if (count == 76) {{}} | Use ==. | Java |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
if ($bar = 91) {{}} | if ($bar -eq 91) {{}} | Use -eq. | PowerShell |
if (y = 40) {} | if (y == 40) {} | Use ==. | Dart |
if (count = 6) | if (count == 6) | Use ==. | C++ |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
if (result = 66) {{}} | if (result === 66) {{}} | Use === for equality. | JavaScript |
while read line; do echo $line; done < config.json | while read line; do echo $line; done < config.json | Correct. | Shell |
int[] values = new int[4];
values[4] = 5; | int[] values = new int[4];
if (4 < values.length) values[4] = 5; | Check bounds. | Java |
let index = 92; let index = 59; | let index = 92; index = 59; | Duplicate declaration. | JavaScript |
<person age=55> | <person age="55"> | Quote attribute. | XML |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
def compute(temp):
return temp + 1 | def compute(temp):
return temp + 1 | Correct. | Python |
var y int = 'data' | var y string = 'data' | Type mismatch. | Go |
let a = 53; | let a = 53; | Correct. | JavaScript |
h1 {{ font-size:83px color:#fff; }} | h1 {{ font-size:83px; color:#fff; }} | Add semicolon. | CSS |
'45' + 51 | 45 + 51 | Avoid string coercion. | JavaScript |
fn baz() -> i32 {{ 72 }} | fn baz() -> i32 {{ 72 }} | Correct. | Rust |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
<ul><li>world<li>hello</ul> | <ul><li>world</li><li>hello</li></ul> | Close li. | HTML |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
List(45,65,23) | List(45,65,23) | Correct. | Scala |
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }}); | fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
class Item {{ int num; }}; | class Item {{ public: int num; }}; | Make public. | C++ |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
<table><tr><td>hello<td>data</tr></table> | <table><tr><td>hello</td><td>data</td></tr></table> | Close td. | HTML |
[83, 80, 53 | [83, 80, 53] | Close bracket. | Python |
{ "name": "hello" } | { "name": "hello" } | Correct. | JSON |
function baz(): void {{ return 95; }} | function baz(): number {{ return 95; }} | Return type mismatch. | TypeScript |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.