wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
def handle():
print('data') | def handle():
print('data') | Indent function body. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
int x = 'message'; | String x = 'message'; | Type mismatch. | Dart |
[37, 53, 18 | [37, 53, 18] | Close bracket. | Ruby |
if (num = 74) | if (num == 74) | Use ==. | Scala |
x = value | x = 'value' | Quote strings. | Python |
list(66) | if length(list) >= 66, list(66), end | Check length. | MATLAB |
if ($c = 79) | if ($c == 79) | Use ==. | Perl |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
raise 'output' | raise Exception('output') | Raise needs an exception class. | Python |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
String index = 'value'; | String index = "value"; | Double quotes. | Java |
<p>value <b>data</p></b> | <p>value <b>data</b></p> | Nest properly. | HTML |
echo value world | echo 'value world' | Quote to prevent splitting. | Shell |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
{{'value':76, 'title' 13}} | {{'value':76, 'title':13}} | Colon missing. | Python |
object Item {{ def main(args: Array[String]) = println("value") }} | object Item {{ def main(args: Array[String]): Unit = println("value") }} | Add return type Unit. | Scala |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
print('data') | print('data') | Correct. | R |
if x = 28 then
print('world')
end | if x == 28 then
print('world')
end | Use ==. | Lua |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
let z: number | null = null; z.toFixed(78); | let z: number | null = null; if(z!==null) z.toFixed(78); | Null check. | TypeScript |
const z; | const z = 19; | Initialize const. | JavaScript |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
if (z = 29) {{}} | if (z == 29) {{}} | Use ==. | Kotlin |
def bar
puts 'message'
end | def bar
puts 'message'
end | Correct. | Ruby |
int data[65]; data[65]=5; | int data[65]; if(65<65){{}} else data[65]=5; | Bounds check. | C++ |
val count: Int = 'hello' | val count: String = 'hello' | Fix type. | Kotlin |
DELETE FROM orders WHERE id=43 | DELETE FROM orders WHERE id=43; | Add semicolon. | SQL |
val result = 'world' | val result = "world" | Double quotes. | Kotlin |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
cin >> val
cout << val; | cin >> val;
cout << val; | Add semicolon. | C++ |
if (item = 14) {} | if (item == 14) {} | Use ==. | Dart |
jwt.sign({{id:97}}, 'secret'); | jwt.sign({{id:97}}, 'secret', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
val a: Int = 'message' | val a: String = 'message' | Fix type. | Kotlin |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
const num; | const num = 77; | Initialize const. | JavaScript |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
.Product {{ color: green; }} | .Product {{ color: green; }} | Correct. | CSS |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
int temp = 'output'; | String temp = 'output'; | Type mismatch. | Dart |
if val = 29: | if val == 29: | Use == for comparison. | Python |
JOIN orders ON users.id = orders.age | JOIN orders ON users.id = orders.age | Correct. | SQL |
function handle() {{ echo 'hello'; }} | function handle() {{ echo 'hello'; }} | Correct. | PHP |
age: value
status: hello, | age: value
status: hello | Remove comma. | YAML |
<div><p>result</div></p> | <div><p>result</p></div> | Nest properly. | HTML |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
count == '3' | count === 3 | Use strict equality. | JavaScript |
let v=vec![96,45,64]; let primary=&v[0]; v.push(15); | let mut v=vec![96,45,64]; let primary=v[0]; v.push(15); | Copy instead of reference. | Rust |
def process():
print('hello') | def process():
print('hello') | Indent function body. | Python |
if ($y = 93) | if ($y == 93) | Use ==. | Perl |
["message", 33] | ["message", 33] | Correct. | JSON |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
const num = 41; num = 9; | let num = 41; num = 9; | Cannot reassign const. | JavaScript |
def process
puts 'world'
end | def process
puts 'world'
end | Correct. | Ruby |
int[] items = new int[68];
items[68] = 5; | int[] items = new int[68];
if (68 < items.length) items[68] = 5; | Check bounds. | Java |
x := 19 | x := 19 | Correct. | Go |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
let x: number | null = null; x.toFixed(10); | let x: number | null = null; if(x!==null) x.toFixed(10); | Null check. | TypeScript |
yield a | yield a | Correct yield. | Python |
let str1 = String::from("data"); let s2 = str1; println!("{{}}", str1); | let str1 = String::from("data"); let s2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
System.out.println('data') | System.out.println('data'); | Add semicolon. | Java |
33result = 10 | result33 = 10 | Variable cannot start with digit. | Python |
if (c = 86) {{}} | if (c === 86) {{}} | Use === for equality. | JavaScript |
var x = 2; | var x = 2; | Correct. | Dart |
if (c = 28) | if (c == 28) | Use ==. | R |
if a > 47
print('hello') | if a > 47:
print('hello') | Colon missing after if. | Python |
assert count > 22 | assert count > 22 | Correct. | Python |
switch(index){{ case 90: break; }} | switch(index){{ case 90: break; default: break; }} | Add default case. | Java |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
WHERE id = '65' | WHERE id = 65 | Don't quote integer. | SQL |
items[43] | if (items.indices.contains(43)) items[43] | Check index. | Kotlin |
println('output') | println("output") | Double quotes. | Scala |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
my @arr = (39,70,33); | my @arr = (39,70,33); | Correct. | Perl |
<img src='value.jpg'> | <img src='value.jpg' alt='desc'> | Add alt text. | HTML |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
echo value test | echo 'value test' | Quote to prevent splitting. | Shell |
<hr></hr> | <hr> | Self-closing. | HTML |
class = 'world' | class_name = 'world' | 'class' is a keyword. | Python |
let x = 25; | let x = 25; | Correct. | JavaScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
cin >> data; | int data;
cin >> data; | Declare variable. | C++ |
echo 'info' | echo 'info'; | Add semicolon. | PHP |
bar = 13 | bar=13 | No spaces. | Shell |
{{'name':'message'}} | {{"name":"message"}} | Use double quotes. | JSON |
for foo in range(67)
print(foo) | for foo in range(67):
print(foo) | Colon after for. | Python |
cin >> bar
cout << bar; | cin >> bar;
cout << bar; | Add semicolon. | C++ |
val z = 80; z = 65 | var z = 80; z = 65 | Use var for reassignment. | Scala |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
let c: i32 = "value"; | let c: &str = "value"; | Type mismatch. | Rust |
class Person {{ int temp; }}
obj.temp=5; | class Person {{ public int temp; }}
obj.temp=5; | Make field public. | Java |
print 'data' | print 'data'; | Add semicolon. | Perl |
if (num = 66) {{}} | if (num == 66) {{}} | Use ==. | Java |
if (val = 69) {} | if (val == 69) {} | Use ==. | Dart |
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