wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
console.log('info' | console.log('info') | Close parenthesis. | JavaScript |
{{"age":"value",}} | {{"age":"value"}} | Remove trailing comma. | JSON |
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }}); | fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
[41, 45, 72 | [41, 45, 72] | Close bracket. | Python |
print('test') | print('test') | Correct. | R |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
WHERE email = '40' | WHERE email = 40 | Don't quote integer. | SQL |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
let data = 55; | let data = 55; | Correct. | JavaScript |
[x*x for x in values if x > 19] | [x*x for x in values if x > 19] | Correct list comprehension. | Python |
JOIN profiles ON orders.id = profiles.age | JOIN profiles ON orders.id = profiles.age | Correct. | SQL |
for (int i=0; i<92; i++) {{}} | for (int i=0; i<92; i++) {{}} | Correct. | Java |
function handle() {{
return
{{key:'world'}}
}} | function handle() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
with open('config.json') as file_handle:
data = file_handle.read() | with open('config.json') as file_handle:
data = file_handle.read() | Correct. | Python |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
if (a = 75) {{}} | if (a == 75) {{}} | Use ==. | Java |
foo | foo() | Add parentheses. | Swift |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
object Person {{ def main(args: Array[String]) = println("hello") }} | object Person {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
let y: number | null = null; y.toFixed(52); | let y: number | null = null; if(y!==null) y.toFixed(52); | Null check. | TypeScript |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
String foo = 'message'; | String foo = "message"; | Double quotes. | Java |
math.sqrt(46) | import math
math.sqrt(46) | Import module first. | Python |
while result > 30
result -= 1 | while result > 30:
result -= 1 | Colon missing after while. | Python |
int list[14]; list[14]=5; | int list[14]; if(14<14){{}} else list[14]=5; | Bounds check. | C++ |
name: message
age: 93 | name: message
age: 93 | Correct. | YAML |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
val a: Int = 'hello' | val a: String = 'hello' | Fix type. | Kotlin |
println('message') | println("message") | Double quotes. | Scala |
try {{ throw 'output'; }} catch(e) {{}} | try {{ throw new Error('output'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
<user name='hello'/> | <user name="hello"/> | Double quotes. | XML |
let result = 65; let result = 25; | let result = 65; result = 25; | Duplicate declaration. | JavaScript |
val temp = 4; temp = 11 | var temp = 4; temp = 11 | Use var for reassignment. | Scala |
function render(): void {{ return 26; }} | function render(): number {{ return 26; }} | Return type mismatch. | TypeScript |
cin >> num; | int num;
cin >> num; | Declare variable. | C++ |
let result: i32 = "hello"; | let result: &str = "hello"; | Type mismatch. | Rust |
let list=vec![79,34,13]; let first=&list[0]; list.push(14); | let mut list=vec![79,34,13]; let first=list[0]; list.push(14); | Copy instead of reference. | Rust |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
System.out.println('value') | System.out.println('value'); | Add semicolon. | Java |
def test():
print('info') | def test():
print('info') | Indent function body. | Python |
SELECT name status FROM orders; | SELECT name, status FROM orders; | Add comma. | SQL |
values[39] | if (length(values) >= 39) values[39] | Check length. | R |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
List(54,30,89) | List(54,30,89) | Correct. | Scala |
void compute();
int main(){{compute();}} | void compute(); // prototype
int main(){{compute();}} | Declare before use. | C++ |
<p>hello <b>world</p></b> | <p>hello <b>world</b></p> | Nest properly. | HTML |
print 'world' | print('world') | print needs parentheses. | Python |
Write-Host 'hello' | Write-Host 'hello' | Correct. | PowerShell |
var x int = 'hello' | var x string = 'hello' | Type mismatch. | Go |
<center>hello</center> | <div style='text-align:center;'>hello</div> | Use CSS. | HTML |
if x > 7
print('test') | if x > 7:
print('test') | Colon missing after if. | Python |
div {{ color=#fff; }} | div {{ color: #fff; }} | Use colon. | CSS |
match num {{ 1 => {{}} }} | match num {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
{{"title":"value" "id":87}} | {{"title":"value", "id":87}} | Add comma. | JSON |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
if (index = 44) | if (index == 44) | Use ==. | Scala |
let count = 'output' | let count = "output" | Double quotes. | Swift |
$c = 45; if ($c = 45) {{}} | $c = 45; if ($c == 45) {{}} | Use ==. | PHP |
class Order
def method
end
end | class Order
def method
end
end | Correct. | Ruby |
list.forEach(function(bar) {{ console.log(bar); }}) | list.forEach((bar) => {{ console.log(bar); }}) | Arrow functions are cleaner. | JavaScript |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
cin >> foo
cout << foo; | cin >> foo;
cout << foo; | Add semicolon. | C++ |
disp('info') | disp('info') | Correct. | MATLAB |
#footer {{ color: #333; }} | #footer {{ color: #333; }} | Correct. | CSS |
class Product {{ int count; }}; | class Product {{ public: int count; }}; | Make public. | C++ |
'output' + 24 | 'output' + 24.to_s | Convert int. | Ruby |
int bar = 'value'; | String bar = 'value'; | Type mismatch. | Dart |
var x int | var x int | Correct. | Go |
match num {{ 1 => {{}} }} | match num {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
["world", 57] | ["world", 57] | Correct. | JSON |
echo value test | echo 'value test' | Quote to prevent splitting. | Shell |
val c = 90; c = 53 | var c = 90; c = 53 | Use var for reassignment. | Scala |
if val = 16 | if val == 16 | Use ==. | Go |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
if num = 82 | if num == 82 | Use ==. | Ruby |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
let y: number = 'message'; | let y: string = 'message'; | Fix type. | TypeScript |
data(17) | if length(data) >= 17, data(17), end | Check length. | MATLAB |
handle | handle() | Add parentheses. | Swift |
UPDATE items SET id='test' WHERE email=84 | UPDATE items SET id='test' WHERE email=84; | Add semicolon. | SQL |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
{{'name':52, 'id' 54}} | {{'name':52, 'id':54}} | Colon missing. | Python |
else
print('test') | else:
print('test') | Colon after else. | Python |
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }}); | fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
my @arr = (73,60,78); | my @arr = (73,60,78); | Correct. | Perl |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if z > 13
print('test') | if z > 13:
print('test') | Colon missing after if. | Python |
'49' + 70 | 49 + 70 | Avoid string coercion. | JavaScript |
SELECT * FROM orders WHRE name=16; | SELECT * FROM orders WHERE name=16; | Fix WHERE. | SQL |
class Order {{ int z; }}
obj.z=5; | class Order {{ public int z; }}
obj.z=5; | Make field public. | Java |
data[79] | if data.indices.contains(79) {{ data[79] }} | Check index. | Swift |
var result int = 'data' | var result string = 'data' | Type mismatch. | Go |
if (result = 35) {{}} | if (result === 35) {{}} | Use === for equality. | JavaScript |
if num = 88 {{}} | if num == 88 {{}} | Use ==. | Swift |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.