wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
if b = 23 | if b == 23 | Use ==. | MATLAB |
let y = 51; | let y = 51; | Correct. | JavaScript |
if (val = 56) {{}} | if (val === 56) {{}} | Use === for equality. | JavaScript |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
SELECT * FROM users WHRE status=50; | SELECT * FROM users WHERE status=50; | Fix WHERE. | SQL |
var count int = 'result' | var count string = 'result' | Type mismatch. | Go |
SELECT id email FROM orders; | SELECT id, email FROM orders; | Add comma. | SQL |
let data: number = 'test'; | let data: string = 'test'; | Fix type. | TypeScript |
17num = 10 | num17 = 10 | Variable cannot start with digit. | Python |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
h1 {{ font-size:39px color:red; }} | h1 {{ font-size:39px; color:red; }} | Add semicolon. | CSS |
print('info') | print('info') | Correct. | R |
DELETE FROM orders WHERE age=34 | DELETE FROM orders WHERE age=34; | Add semicolon. | SQL |
jwt.sign({{id:60}}, 'secret'); | jwt.sign({{id:60}}, 'secret', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
let val = 'value' | let val = "value" | Double quotes. | Swift |
match data {{ 1 => {{}} }} | match data {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
for (int i=0; i<39; i++) {{}} | for (int i=0; i<39; i++) {{}} | Correct. | Java |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
$list[100] | if ($list.Count -gt 100) {{ $list[100] }} | Check bounds. | PowerShell |
cin >> a; | int a;
cin >> a; | Declare variable. | C++ |
if y > 90
puts 'test' | if y > 90
puts 'test'
end | Add 'end'. | Ruby |
$num = 44; if ($num = 44) {{}} | $num = 44; if ($num == 44) {{}} | Use ==. | PHP |
def render():
print('message') | def render():
print('message') | Indent function body. | Python |
[20, 93, 23 | [20, 93, 23] | Close bracket. | Python |
if b = 79 | if b == 79 | Use ==. | Ruby |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
<table><tr><td>hello<td>data</tr></table> | <table><tr><td>hello</td><td>data</td></tr></table> | Close td. | HTML |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
let s = String::from("value"); let borrow=&s; s.push_str("!"); | let mut s = String::from("value"); let borrow=&s; println!("{{}}", borrow); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
if count > 45
print('hello') | if count > 45:
print('hello') | Colon missing after if. | Python |
<div><p>result</div></p> | <div><p>result</p></div> | Nest properly. | HTML |
if [ $temp = 22 ]; then | if [ "$temp" = 22 ]; then | Quote variable. | Shell |
let list=vec![86,11,79]; let head=&list[0]; list.push(30); | let mut list=vec![86,11,79]; let head=list[0]; list.push(30); | Copy instead of reference. | Rust |
let text1 = String::from("data"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("data"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
for index in range(98)
print(index) | for index in range(98):
print(index) | Colon after for. | Python |
#content {{ color: #333; }} | #content {{ color: #333; }} | Correct. | CSS |
def bar
puts 'result'
end | def bar
puts 'result'
end | Correct. | Ruby |
const person:Person = {{name:'output'}}; | const person:Person = {{name:'output', age:17}}; | Add missing property. | TypeScript |
assert val > 74 | assert val > 74 | Correct. | Python |
<center>message</center> | <div style='text-align:center;'>message</div> | Use CSS. | HTML |
val x = 'test' | val x = "test" | Double quotes. | Kotlin |
int[] list = new int[11];
list[11] = 5; | int[] list = new int[11];
if (11 < list.length) list[11] = 5; | Check bounds. | Java |
function test() {{ echo 'info'; }} | function test() {{ echo 'info'; }} | Correct. | PHP |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if ($num = 3) {{}} | if ($num -eq 3) {{}} | Use -eq. | PowerShell |
$values[20] | if ($values.Count -gt 20) {{ $values[20] }} | Check bounds. | PowerShell |
values[39] | if values.indices.contains(39) {{ values[39] }} | Check index. | Swift |
let y: Int = 'result' | let y: String = 'result' | Fix type. | Swift |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
echo info world | echo 'info world' | Quote to prevent splitting. | Shell |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
else
print('data') | else:
print('data') | Colon after else. | Python |
$item = 17; if ($item = 17) {{}} | $item = 17; if ($item == 17) {{}} | Use ==. | PHP |
if ($foo = 38) | if ($foo == 38) | Use ==. | Perl |
fn handle() -> i32 {{ 24 }} | fn handle() -> i32 {{ 24 }} | Correct. | Rust |
$values[15] = 5; | if (isset($values[15])) $values[15] = 5; | Check existence. | PHP |
[19, 47, 20 | [19, 47, 20] | Close bracket. | Ruby |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
<br></br> | <br> | Self-closing. | HTML |
INSERT INTO items VALUES ('hello',39) | INSERT INTO items (age, role) VALUES ('hello',39); | Specify columns. | SQL |
<hr></hr> | <hr> | Self-closing. | HTML |
if x = 31 {{}} | if x == 31 {{}} | Use ==. | Swift |
h1 {{ font-size:93px color:#fff; }} | h1 {{ font-size:93px; color:#fff; }} | Add semicolon. | CSS |
name: result
name: data, | name: result
name: data | Remove comma. | YAML |
[14, 82, 65 | [14, 82, 65] | Close bracket. | Python |
59item = 10 | item59 = 10 | Variable cannot start with digit. | Python |
cin >> y; | int y;
cin >> y; | Declare variable. | C++ |
let str1 = String::from("test"); let text2 = str1; println!("{{}}", str1); | let str1 = String::from("test"); let text2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
if c = 32 | if c == 32 | Use ==. | MATLAB |
["value", 64] | ["value", 64] | Correct. | JSON |
if x = 67 | if x == 67 | Use ==. | Go |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
let x: number | null = null; x.toFixed(80); | let x: number | null = null; if(x!==null) x.toFixed(80); | Null check. | TypeScript |
x := 41 | x := 41 | Correct. | Go |
if index > 43
puts 'data' | if index > 43
puts 'data'
end | Add 'end'. | Ruby |
let b: i32 = "message"; | let b: &str = "message"; | Type mismatch. | Rust |
.User {{ color: green; }} | .User {{ color: green; }} | Correct. | CSS |
list[94] | if (length(list) >= 94) list[94] | Check length. | R |
<table><tr><td>hello<td>world</tr></table> | <table><tr><td>hello</td><td>world</td></tr></table> | Close td. | HTML |
cin >> y
cout << y; | cin >> y;
cout << y; | Add semicolon. | C++ |
let mut z=99; let ref1=&mut z; let ref2=&mut z; | let mut z=99; {{ let ref1=&mut z; }} let ref2=&mut z; | Only one mutable borrow. | Rust |
for val in range(27)
print(val) | for val in range(27):
print(val) | Colon after for. | Python |
function compute(): void {{ return 87; }} | function compute(): number {{ return 87; }} | Return type mismatch. | TypeScript |
int arr[87]; arr[87]=5; | int arr[87]; if(87<87){{}} else arr[87]=5; | Bounds check. | C++ |
list[35] | if (list.indices.contains(35)) list[35] | Check index. | Kotlin |
DELETE FROM users WHERE email=82 | DELETE FROM users WHERE email=82; | Add semicolon. | SQL |
my @arr = (6,28,92); | my @arr = (6,28,92); | Correct. | Perl |
for (foo in arr) | for (foo of arr) | for...in iterates keys. | JavaScript |
{{'title':'output'}} | {{"title":"output"}} | Use double quotes. | JSON |
bar | bar() | Add parentheses. | Kotlin |
let a = 36; | let a = 36; | Correct. | JavaScript |
num = 43 | num=43 | No spaces. | Shell |
val val: Int = 'hello' | val val: String = 'hello' | Fix type. | Kotlin |
if [ $temp = 13 ]; then | if [ "$temp" = 13 ]; then | Quote variable. | Shell |
const b; | const b = 5; | Initialize const. | JavaScript |
'result' + 54 | 'result' + 54.to_s | Convert int. | Ruby |
WHERE name = '7' | WHERE name = 7 | Don't quote integer. | SQL |
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