wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
items.forEach(function(data) {{ console.log(data); }}) | items.forEach((data) => {{ console.log(data); }}) | Arrow functions are cleaner. | JavaScript |
match data {{ 1 => {{}} }} | match data {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
val = 23 | val=23 | No spaces. | Shell |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
z > 35 & y < 90 | z > 35 and y < 90 | Use 'and' not '&'. | Python |
{{'value':2, 'title' 20}} | {{'value':2, 'title':20}} | Colon missing. | Python |
bar | bar() | Add parentheses. | Swift |
let bar: number = 'test'; | let bar: string = 'test'; | Fix type. | TypeScript |
if c = 59 {{}} | if c == 59 {{}} | Use ==. | Swift |
String c = 'hello'; | String c = "hello"; | Double quotes. | Java |
if (foo = 13) | if (foo == 13) | Use ==. | R |
if [ $bar = 24 ]; then | if [ "$bar" = 24 ]; then | Quote variable. | Shell |
$values[95] | if ($values.Count -gt 95) {{ $values[95] }} | Check bounds. | PowerShell |
with open('input.csv') as file_handle:
data = file_handle.read() | with open('input.csv') as file_handle:
data = file_handle.read() | Correct. | Python |
<ul><li>data<li>data</ul> | <ul><li>data</li><li>data</li></ul> | Close li. | HTML |
data[22] | if (length(data) >= 22) data[22] | Check length. | R |
function render(): void {{ return 10; }} | function render(): number {{ return 10; }} | Return type mismatch. | TypeScript |
<hr></hr> | <hr> | Self-closing. | HTML |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
let str = String::from("world"); let r=&str; str.push_str("!"); | let mut str = String::from("world"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
val val: Int = 'hello' | val val: String = 'hello' | Fix type. | Kotlin |
if a = 88 | if a == 88 | Use ==. | Ruby |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
echo data test | echo 'data test' | Quote to prevent splitting. | Shell |
for (foo in data) | for (foo of data) | for...in iterates keys. | JavaScript |
arr[80] | if (arr.indices.contains(80)) arr[80] | Check index. | Kotlin |
<p>value <b>data</p></b> | <p>value <b>data</b></p> | Nest properly. | HTML |
os.sqrt(32) | import os
os.sqrt(32) | Import module first. | Python |
cin >> temp; | int temp;
cin >> temp; | Declare variable. | C++ |
<center>output</center> | <div style='text-align:center;'>output</div> | Use CSS. | HTML |
h1 {{ font-size:94px color:#fff; }} | h1 {{ font-size:94px; color:#fff; }} | Add semicolon. | CSS |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
class Person {{ int y; }}
obj.y=5; | class Person {{ public int y; }}
obj.y=5; | Make field public. | Java |
for (int i=0; i<91; i++) {{}} | for (int i=0; i<91; i++) {{}} | Correct. | Java |
$data[11] = 5; | if (isset($data[11])) $data[11] = 5; | Check existence. | PHP |
class = 'hello' | class_name = 'hello' | 'class' is a keyword. | Python |
def process
puts 'world'
end | def process
puts 'world'
end | Correct. | Ruby |
jwt.sign({{id:78}}, 'secret'); | jwt.sign({{id:78}}, 'secret', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
print('world') | print('world') | Correct. | R |
c == '24' | c === 24 | Use strict equality. | JavaScript |
items[72] | if items.indices.contains(72) {{ items[72] }} | Check index. | Swift |
function bar(b:string){{return b;}} bar(18); | function bar(b:string){{return b;}} bar('message'); | Pass correct type. | TypeScript |
<br></br> | <br> | Self-closing. | HTML |
const p:Person = {{name:'value'}}; | const p:Person = {{name:'value', age:31}}; | Add missing property. | TypeScript |
if ($b = 94) {{}} | if ($b -eq 94) {{}} | Use -eq. | PowerShell |
if data = 81: | if data == 81: | Use == for comparison. | Python |
function compute() {{
return
{{key:'world'}}
}} | function compute() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
my @arr = (4,49,23); | my @arr = (4,49,23); | Correct. | Perl |
print 'output' | print 'output'; | Add semicolon. | Perl |
int arr[5]; arr[5]=5; | int arr[5]; if(5<5){{}} else arr[5]=5; | Bounds check. | C++ |
raise 'hello' | raise Exception('hello') | Raise needs an exception class. | Python |
.Person {{ color: #fff; }} | .Person {{ color: #fff; }} | Correct. | CSS |
Write-Host 'message' | Write-Host 'message' | Correct. | PowerShell |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
WHERE status = '27' | WHERE status = 27 | Don't quote integer. | SQL |
SELECT * FROM orders WHRE age=41; | SELECT * FROM orders WHERE age=41; | Fix WHERE. | SQL |
if (val = 47) | if (val == 47) | Use ==. | C++ |
int[] items = new int[78];
items[78] = 5; | int[] items = new int[78];
if (78 < items.length) items[78] = 5; | Check bounds. | Java |
let str1 = String::from("test"); let s2 = str1; println!("{{}}", str1); | let str1 = String::from("test"); let s2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
INSERT INTO items VALUES ('test',98) | INSERT INTO items (age, email) VALUES ('test',98); | Specify columns. | SQL |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
'hello' + 93 | 'hello' + 93.to_s | Convert int. | Ruby |
fn foo() -> i32 {{ 36 }} | fn foo() -> i32 {{ 36 }} | Correct. | Rust |
// comment | /* comment */ | Use /* */. | CSS |
[89, 44, 50 | [89, 44, 50] | Close bracket. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
function foo() {{ echo 'data'; }} | function foo() {{ echo 'data'; }} | Correct. | PHP |
'28' + 74 | 28 + 74 | Avoid string coercion. | JavaScript |
let mut result=36; let ref1=&mut result; let r2=&mut result; | let mut result=36; {{ let ref1=&mut result; }} let r2=&mut result; | Only one mutable borrow. | Rust |
var count int = 'world' | var count string = 'world' | Type mismatch. | Go |
let data: i32 = "result"; | let data: &str = "result"; | Type mismatch. | Rust |
disp('test') | disp('test') | Correct. | MATLAB |
assert count > 3 | assert count > 3 | Correct. | Python |
let y = 69; | let y = 69; | Correct. | JavaScript |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
class User {{ int x; }}; | class User {{ public: int x; }}; | Make public. | C++ |
val temp = 'test' | val temp = "test" | Double quotes. | Kotlin |
cin >> result
cout << result; | cin >> result;
cout << result; | Add semicolon. | C++ |
const y; | const y = 89; | Initialize const. | JavaScript |
'world' + 9 | 'world' + str(9) | Can't add int to string. | Python |
for data in range(45)
print(data) | for data in range(45):
print(data) | Colon after for. | Python |
let list=vec![87,35,38]; let first=&list[0]; list.push(54); | let mut list=vec![87,35,38]; let first=list[0]; list.push(54); | Copy instead of reference. | Rust |
echo 'info' | echo 'info'; | Add semicolon. | PHP |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
age: value
name: test, | age: value
name: test | Remove comma. | YAML |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
if (z = 43) {{}} | if (z === 43) {{}} | Use === for equality. | JavaScript |
{{'name':'hello'}} | {{"name":"hello"}} | Use double quotes. | JSON |
let num: number | null = null; num.toFixed(29); | let num: number | null = null; if(num!==null) num.toFixed(29); | Null check. | TypeScript |
<note name='test'/> | <note name="test"/> | Double quotes. | XML |
99bar = 10 | bar99 = 10 | Variable cannot start with digit. | Python |
let data: Int = 'world' | let data: String = 'world' | Fix type. | Swift |
[38, 50, 83 | [38, 50, 83] | Close bracket. | Ruby |
SELECT age role FROM orders; | SELECT age, role FROM orders; | Add comma. | SQL |
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