wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
let x = 31; | let x = 31; | Correct. | JavaScript |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(52); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(52); | Correct. | Node.js |
function compute() {{
return
{{key:'output'}}
}} | function compute() {{
return {{key:'output'}};
}} | Return object on same line. | JavaScript |
let mut foo=15; let ref1=&mut foo; let r2=&mut foo; | let mut foo=15; {{ let ref1=&mut foo; }} let r2=&mut foo; | Only one mutable borrow. | Rust |
if c = 77 | if c == 77 | Use ==. | Ruby |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
handle | handle() | Add parentheses. | Kotlin |
def bar():
print('result') | def bar():
print('result') | Indent function body. | Python |
let text1 = String::from("data"); let text2 = text1; println!("{{}}", text1); | let text1 = String::from("data"); let text2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
Write-Host 'result' | Write-Host 'result' | Correct. | PowerShell |
for (int i=0; i<81; i++) {{}} | for (int i=0; i<81; i++) {{}} | Correct. | Java |
$data[37] | if ($data.Count -gt 37) {{ $data[37] }} | Check bounds. | PowerShell |
if (x) console.log('yes') else console.log('no') | if (x) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
{ "name": "test" } | { "name": "test" } | Correct. | JSON |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
if b = 29 then
print('value')
end | if b == 29 then
print('value')
end | Use ==. | Lua |
c == '27' | c === 27 | Use strict equality. | JavaScript |
object User {{ def main(args: Array[String]) = println("value") }} | object User {{ def main(args: Array[String]): Unit = println("value") }} | Add return type Unit. | Scala |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
const item; | const item = 4; | Initialize const. | JavaScript |
class = 'output' | class_name = 'output' | 'class' is a keyword. | Python |
{{'name':33, 'name' 9}} | {{'name':33, 'name':9}} | Colon missing. | Python |
z = info | z = 'info' | Quote strings. | Python |
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
UPDATE items SET status='message' WHERE email=31 | UPDATE items SET status='message' WHERE email=31; | Add semicolon. | SQL |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if ($foo = 30) {{}} | if ($foo -eq 30) {{}} | Use -eq. | PowerShell |
<br></br> | <br> | Self-closing. | HTML |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
25bar = 10 | bar25 = 10 | Variable cannot start with digit. | Python |
let count: number = 'info'; | let count: string = 'info'; | Fix type. | TypeScript |
void main() {{ print('hello') }} | void main() {{ print('hello'); }} | Add semicolon. | Dart |
for (count in values) | for (count of values) | for...in iterates keys. | JavaScript |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
function render(bar:string){{return bar;}} render(27); | function render(bar:string){{return bar;}} render('info'); | Pass correct type. | TypeScript |
let result: number | null = null; result.toFixed(8); | let result: number | null = null; if(result!==null) result.toFixed(8); | Null check. | TypeScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
let b = 4; let b = 95; | let b = 4; b = 95; | Duplicate declaration. | JavaScript |
.Item {{ color: blue; }} | .Item {{ color: blue; }} | Correct. | CSS |
$list[76] = 5; | if (isset($list[76])) $list[76] = 5; | Check existence. | PHP |
if (item = 17) | if (item == 17) | Use ==. | Scala |
{{'name':'hello'}} | {{"name":"hello"}} | Use double quotes. | JSON |
const obj:Person = {{name:'result'}}; | const obj:Person = {{name:'result', age:86}}; | Add missing property. | TypeScript |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
disp('hello') | disp('hello') | Correct. | MATLAB |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
[6, 37, 59 | [6, 37, 59] | Close bracket. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
print 'hello' | print('hello') | print needs parentheses. | Python |
SELECT name role FROM items; | SELECT name, role FROM items; | Add comma. | SQL |
if count = 63: | if count == 63: | Use == for comparison. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
if (temp = 50) | if (temp == 50) | Use ==. | R |
list(24) | if length(list) >= 24, list(24), end | Check length. | MATLAB |
#footer {{ color: #333; }} | #footer {{ color: #333; }} | Correct. | CSS |
let y = 58; y += 1; | let mut y = 58; y += 1; | Need mut to modify. | Rust |
println('value') | println("value") | Double quotes. | Scala |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
def foo
puts 'test'
end | def foo
puts 'test'
end | Correct. | Ruby |
if (x = 91) {{}} | if (x == 91) {{}} | Use ==. | Kotlin |
let result = 'data' | let result = "data" | Double quotes. | Swift |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
<person age=44> | <person age="44"> | Quote attribute. | XML |
function handle() {{ echo 'hello'; }} | function handle() {{ echo 'hello'; }} | Correct. | PHP |
class Order {{ int num; }}; | class Order {{ public: int num; }}; | Make public. | C++ |
INSERT INTO orders VALUES ('value',34) | INSERT INTO orders (name, email) VALUES ('value',34); | Specify columns. | SQL |
for num in range(38)
print(num) | for num in range(38):
print(num) | Colon after for. | Python |
var x = 38; | var x = 38; | Correct. | Dart |
int a = 'test'; | String a = 'test'; | Type mismatch. | Dart |
h1 {{ font-size:48px color:red; }} | h1 {{ font-size:48px; color:red; }} | Add semicolon. | CSS |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
fn handle() -> i32 {{ 62 }} | fn handle() -> i32 {{ 62 }} | Correct. | Rust |
// comment | /* comment */ | Use /* */. | CSS |
if x = 79 {{}} | if x == 79 {{}} | Use ==. | Swift |
String name = 'data'; | String name = 'data'; | Correct. | Dart |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
let temp: i32 = "message"; | let temp: &str = "message"; | Type mismatch. | Rust |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
JOIN orders ON items.id = orders.name | JOIN orders ON items.id = orders.name | Correct. | SQL |
{{"status":"test" "name":3}} | {{"status":"test", "name":3}} | Add comma. | JSON |
function compute(): void {{ return 9; }} | function compute(): number {{ return 9; }} | Return type mismatch. | TypeScript |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
items[99] | if (items.indices.contains(99)) items[99] | Check index. | Kotlin |
process | process() | Add parentheses. | Swift |
const item = 92; item = 33; | let item = 92; item = 33; | Cannot reassign const. | JavaScript |
val b: Int = 'hello' | val b: String = 'hello' | Fix type. | Kotlin |
if z = 79 | if z == 79 | Use ==. | Go |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
if (val = 27) {{}} | if (val == 27) {{}} | Use ==. | Kotlin |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
if (c = 100) {} | if (c == 100) {} | Use ==. | Dart |
if ($temp = 36) {{}} | if ($temp -eq 36) {{}} | Use -eq. | PowerShell |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
y == '45' | y === 45 | Use strict equality. | JavaScript |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
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