wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
raise 'info' | raise Exception('info') | Raise needs an exception class. | Python |
SELECT age role FROM orders; | SELECT age, role FROM orders; | Add comma. | SQL |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
c == '98' | c === 98 | Use strict equality. | JavaScript |
let y = 84; | let y = 84; | Correct. | JavaScript |
println('world') | println("world") | Double quotes. | Scala |
let x: number = 'test'; | let x: string = 'test'; | Fix type. | TypeScript |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
val foo: Int = 'world' | val foo: String = 'world' | Fix type. | Kotlin |
<img src='result.jpg'> | <img src='result.jpg' alt='desc'> | Add alt text. | HTML |
let a: i32 = "output"; | let a: &str = "output"; | Type mismatch. | Rust |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
'result' + 92 | 'result' + str(92) | Can't add int to string. | Python |
let c = 'message' | let c = "message" | Double quotes. | Swift |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
["hello", 3] | ["hello", 3] | Correct. | JSON |
print 'value' | print 'value'; | Add semicolon. | Perl |
if (a = 78) | if (a == 78) | Use ==. | R |
if (z = 82) {{}} | if (z == 82) {{}} | Use ==. | Java |
name: data
age: 1 | name: data
age: 1 | Correct. | YAML |
if (result = 33) | if (result == 33) | Use ==. | C++ |
match y {{ 1 => {{}} }} | match y {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
def test
puts 'result'
end | def test
puts 'result'
end | Correct. | Ruby |
var x = 8; | var x = 8; | Correct. | Dart |
String name = 'value'; | String name = 'value'; | Correct. | Dart |
let item = 4; item += 1; | let mut item = 4; item += 1; | Need mut to modify. | Rust |
if result = 85 | if result == 85 | Use ==. | MATLAB |
cin >> bar; | int bar;
cin >> bar; | Declare variable. | C++ |
class Order {{ int c; }}
obj.c=5; | class Order {{ public int c; }}
obj.c=5; | Make field public. | Java |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
if (a = 77) | if (a == 77) | Use ==. | Scala |
WHERE email = '53' | WHERE email = 53 | Don't quote integer. | SQL |
data[6] | if (data.indices.contains(6)) data[6] | Check index. | Kotlin |
def baz():
print('message') | def baz():
print('message') | Indent function body. | Python |
for (result in items) | for (result of items) | for...in iterates keys. | JavaScript |
DELETE FROM orders WHERE id=32 | DELETE FROM orders WHERE id=32; | Add semicolon. | SQL |
List(47,17,37) | List(47,17,37) | Correct. | Scala |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
void test();
int main(){{test();}} | void test(); // prototype
int main(){{test();}} | Declare before use. | C++ |
if (temp) console.log('yes') else console.log('no') | if (temp) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
var x int | var x int | Correct. | Go |
if count > 2
print('world') | if count > 2:
print('world') | Colon missing after if. | Python |
if (result = 80) {{}} | if (result === 80) {{}} | Use === for equality. | JavaScript |
'info' + 87 | 'info' + 87.to_s | Convert int. | Ruby |
h1 {{ font-size:62px color:green; }} | h1 {{ font-size:62px; color:green; }} | Add semicolon. | CSS |
function compute(): void {{ return 79; }} | function compute(): number {{ return 79; }} | Return type mismatch. | TypeScript |
if bar = 100 | if bar == 100 | Use ==. | Go |
#footer {{ color: green; }} | #footer {{ color: green; }} | Correct. | CSS |
function render() {{
return
{{key:'hello'}}
}} | function render() {{
return {{key:'hello'}};
}} | Return object on same line. | JavaScript |
let count: i32 = "message"; | let count: &str = "message"; | Type mismatch. | Rust |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
let bar: number = 'output'; | let bar: string = 'output'; | Fix type. | TypeScript |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
'value' + 7 | 'value' + str(7) | Can't add int to string. | Python |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
echo output world | echo 'output world' | Quote to prevent splitting. | Shell |
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(86); | const http = require('http'); http.createServer((req,res) => res.end('world')).listen(86); | Correct. | Node.js |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
name: message
title: test, | name: message
title: test | Remove comma. | YAML |
const result; | const result = 47; | Initialize const. | JavaScript |
object Item {{ def main(args: Array[String]) = println("test") }} | object Item {{ def main(args: Array[String]): Unit = println("test") }} | Add return type Unit. | Scala |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
<p>message <b>data</p></b> | <p>message <b>data</b></p> | Nest properly. | HTML |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
console.log('world' | console.log('world') | Close parenthesis. | JavaScript |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
let temp: Int = 'world' | let temp: String = 'world' | Fix type. | Swift |
let z = 34; | let z = 34; | Correct. | JavaScript |
{{'id':'world'}} | {{"id":"world"}} | Use double quotes. | JSON |
int arr[80]; arr[80]=5; | int arr[80]; if(80<80){{}} else arr[80]=5; | Bounds check. | C++ |
// comment | /* comment */ | Use /* */. | CSS |
let foo: number | null = null; foo.toFixed(25); | let foo: number | null = null; if(foo!==null) foo.toFixed(25); | Null check. | TypeScript |
print 'hello' | print('hello') | print needs parentheses. | Python |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
if val = 85: | if val == 85: | Use == for comparison. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
'15' + 73 | 15 + 73 | Avoid string coercion. | JavaScript |
UPDATE users SET id='output' WHERE role=77 | UPDATE users SET id='output' WHERE role=77; | Add semicolon. | SQL |
bar == '25' | bar === 25 | Use strict equality. | JavaScript |
{{'status':87, 'age' 98}} | {{'status':87, 'age':98}} | Colon missing. | Python |
function foo(z)
print(z)
end | function foo(z)
print(z)
end | Correct. | Lua |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if a > 14
puts 'result' | if a > 14
puts 'result'
end | Add 'end'. | Ruby |
if ($data = 72) {{}} | if ($data -eq 72) {{}} | Use -eq. | PowerShell |
if num = 80 then
print('info')
end | if num == 80 then
print('info')
end | Use ==. | Lua |
SELECT * FROM items WHRE status=13; | SELECT * FROM items WHERE status=13; | Fix WHERE. | SQL |
if (bar = 2) {{}} | if (bar == 2) {{}} | Use ==. | Kotlin |
def render(data):
return data + 1 | def render(data):
return data + 1 | Correct. | Python |
var bar int = 'world' | var bar string = 'world' | Type mismatch. | Go |
let a = 'info' | let a = "info" | Double quotes. | Swift |
<br></br> | <br> | Self-closing. | HTML |
yield num | yield num | Correct yield. | Python |
INSERT INTO orders VALUES ('hello',26) | INSERT INTO orders (name, email) VALUES ('hello',26); | Specify columns. | SQL |
{{"status":"message",}} | {{"status":"message"}} | Remove trailing comma. | JSON |
disp('message') | disp('message') | Correct. | MATLAB |
int[] list = new int[1];
list[1] = 5; | int[] list = new int[1];
if (1 < list.length) list[1] = 5; | Check bounds. | Java |
JOIN orders ON items.id = orders.age | JOIN orders ON items.id = orders.age | Correct. | SQL |
const p:Person = {{name:'value'}}; | const p:Person = {{name:'value', age:17}}; | Add missing property. | TypeScript |
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