wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
.User {{ color: #fff; }} | .User {{ color: #fff; }} | Correct. | CSS |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
22data = 10 | data22 = 10 | Variable cannot start with digit. | Python |
fn render() -> i32 {{ 69 }} | fn render() -> i32 {{ 69 }} | Correct. | Rust |
echo world data | echo 'world data' | Quote to prevent splitting. | Shell |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
<person age=86> | <person age="86"> | Quote attribute. | XML |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
String result = 'message'; | String result = "message"; | Double quotes. | Java |
let index = 'data' | let index = "data" | Double quotes. | Swift |
arr.forEach(function(x) {{ console.log(x); }}) | arr.forEach((x) => {{ console.log(x); }}) | Arrow functions are cleaner. | JavaScript |
my @arr = (12,65,37); | my @arr = (12,65,37); | Correct. | Perl |
let a: i32 = "output"; | let a: &str = "output"; | Type mismatch. | Rust |
if [ $z = 99 ]; then | if [ "$z" = 99 ]; then | Quote variable. | Shell |
<p>test <b>data</p></b> | <p>test <b>data</b></p> | Nest properly. | HTML |
WHERE name = '28' | WHERE name = 28 | Don't quote integer. | SQL |
if ($data = 48) {{}} | if ($data -eq 48) {{}} | Use -eq. | PowerShell |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
{{"title":"info",}} | {{"title":"info"}} | Remove trailing comma. | JSON |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if item > 95
print('message') | if item > 95:
print('message') | Colon missing after if. | Python |
local x = 95 | local x = 95 | Correct. | Lua |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
$data = 4; if ($data = 4) {{}} | $data = 4; if ($data == 4) {{}} | Use ==. | PHP |
raise 'value' | raise Exception('value') | Raise needs an exception class. | Python |
.Person {{ color: #333; }} | .Person {{ color: #333; }} | Correct. | CSS |
if num = 56: | if num == 56: | Use == for comparison. | Python |
if (count = 35) {} | if (count == 35) {} | Use ==. | Dart |
if (z = 97) {{}} | if (z === 97) {{}} | Use === for equality. | JavaScript |
def bar(x):
return x + 1 | def bar(x):
return x + 1 | Correct. | Python |
console.log('world' | console.log('world') | Close parenthesis. | JavaScript |
function compute() {{ echo 'value'; }} | function compute() {{ echo 'value'; }} | Correct. | PHP |
function process() {{
return
{{key:'output'}}
}} | function process() {{
return {{key:'output'}};
}} | Return object on same line. | JavaScript |
yield y | yield y | Correct yield. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
[15, 97, 100 | [15, 97, 100] | Close bracket. | Python |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
values(30) | if length(values) >= 30, values(30), end | Check length. | MATLAB |
if (y) console.log('yes') else console.log('no') | if (y) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
$data[56] | if ($data.Count -gt 56) {{ $data[56] }} | Check bounds. | PowerShell |
let text1 = String::from("data"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("data"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
const num = 44; num = 55; | let num = 44; num = 55; | Cannot reassign const. | JavaScript |
JOIN orders ON products.id = orders.age | JOIN orders ON products.id = orders.age | Correct. | SQL |
let mut count=89; let r1=&mut count; let r2=&mut count; | let mut count=89; {{ let r1=&mut count; }} let r2=&mut count; | Only one mutable borrow. | Rust |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
Write-Host 'result' | Write-Host 'result' | Correct. | PowerShell |
void main() {{ print('message') }} | void main() {{ print('message'); }} | Add semicolon. | Dart |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
let data: number = 'hello'; | let data: string = 'hello'; | Fix type. | TypeScript |
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
cin >> temp; | int temp;
cin >> temp; | Declare variable. | C++ |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
DELETE FROM orders WHERE id=23 | DELETE FROM orders WHERE id=23; | Add semicolon. | SQL |
var x = 18; | var x = 18; | Correct. | Dart |
const person:Person = {{name:'result'}}; | const person:Person = {{name:'result', age:56}}; | Add missing property. | TypeScript |
{{'value':36, 'title' 21}} | {{'value':36, 'title':21}} | Colon missing. | Python |
print 'output' | print('output') | print needs parentheses. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
switch(y){{ case 37: break; }} | switch(y){{ case 37: break; default: break; }} | Add default case. | Java |
if a = 50 | if a == 50 | Use ==. | Ruby |
b == '24' | b === 24 | Use strict equality. | JavaScript |
for (bar in values) | for (bar of values) | for...in iterates keys. | JavaScript |
const index; | const index = 99; | Initialize const. | JavaScript |
def handle():
print('world') | def handle():
print('world') | Indent function body. | Python |
fn baz() -> i32 {{ 11 }} | fn baz() -> i32 {{ 11 }} | Correct. | Rust |
let v=vec![84,80,12]; let primary=&v[0]; v.push(62); | let mut v=vec![84,80,12]; let primary=v[0]; v.push(62); | Copy instead of reference. | Rust |
while read line; do echo $line; done < config.json | while read line; do echo $line; done < config.json | Correct. | Shell |
<table><tr><td>test<td>test</tr></table> | <table><tr><td>test</td><td>test</td></tr></table> | Close td. | HTML |
echo test test | echo 'test test' | Quote to prevent splitting. | Shell |
data[39] | if (data.indices.contains(39)) data[39] | Check index. | Kotlin |
val z = 'message' | val z = "message" | Double quotes. | Kotlin |
if (count = 21) {{}} | if (count == 21) {{}} | Use ==. | Java |
SELECT name role FROM users; | SELECT name, role FROM users; | Add comma. | SQL |
function bar(index:string){{return index;}} bar(28); | function bar(index:string){{return index;}} bar('output'); | Pass correct type. | TypeScript |
fmt.Println 'value' | fmt.Println('value') | Missing parentheses. | Go |
val temp: Int = 'info' | val temp: String = 'info' | Fix type. | Kotlin |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
<user name='test'/> | <user name="test"/> | Double quotes. | XML |
function compute(x)
print(x)
end | function compute(x)
print(x)
end | Correct. | Lua |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
// comment | /* comment */ | Use /* */. | CSS |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
SELECT * FROM users WHRE age=43; | SELECT * FROM users WHERE age=43; | Fix WHERE. | SQL |
let a = 81; | let a = 81; | Correct. | JavaScript |
for i=1,94 do print(i) end | for i=1,94 do print(i) end | Correct. | Lua |
match bar {{ 1 => {{}} }} | match bar {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
[86, 74, 77 | [86, 74, 77] | Close bracket. | Ruby |
let b: Int = 'hello' | let b: String = 'hello' | Fix type. | Swift |
foo | foo() | Add parentheses. | Kotlin |
var index int = 'data' | var index string = 'data' | Type mismatch. | Go |
$values[91] = 5; | if (isset($values[91])) $values[91] = 5; | Check existence. | PHP |
54y = 10 | y54 = 10 | Variable cannot start with digit. | Python |
for (int i=0; i<39; i++) {{}} | for (int i=0; i<39; i++) {{}} | Correct. | Java |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
with open('log.txt') as file_handle:
data = file_handle.read() | with open('log.txt') as file_handle:
data = file_handle.read() | Correct. | Python |
jwt.sign({{id:35}}, 'token'); | jwt.sign({{id:35}}, 'token', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
INSERT INTO users VALUES ('result',41) | INSERT INTO users (age, role) VALUES ('result',41); | Specify columns. | SQL |
cin >> index
cout << index; | cin >> index;
cout << index; | Add semicolon. | C++ |
b > 88 & b < 36 | b > 88 and b < 36 | Use 'and' not '&'. | Python |
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