wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
<user name='value'/> | <user name="value"/> | Double quotes. | XML |
for (y in values) | for (y of values) | for...in iterates keys. | JavaScript |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
val c = 'hello' | val c = "hello" | Double quotes. | Kotlin |
if index > 57
puts 'result' | if index > 57
puts 'result'
end | Add 'end'. | Ruby |
Write-Host 'value' | Write-Host 'value' | Correct. | PowerShell |
div {{ color=#fff; }} | div {{ color: #fff; }} | Use colon. | CSS |
list[9] | if list.indices.contains(9) {{ list[9] }} | Check index. | Swift |
print 'world' | print('world') | print needs parentheses. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
print 'value' | print 'value'; | Add semicolon. | Perl |
process | process() | Add parentheses. | Swift |
json.sqrt(12) | import json
json.sqrt(12) | Import module first. | Python |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
print('value') | print('value') | Correct. | R |
INSERT INTO items VALUES ('world',82) | INSERT INTO items (name, role) VALUES ('world',82); | Specify columns. | SQL |
class User {{ int bar; }}; | class User {{ public: int bar; }}; | Make public. | C++ |
function test(val)
print(val)
end | function test(val)
print(val)
end | Correct. | Lua |
while read line; do echo $line; done < config.json | while read line; do echo $line; done < config.json | Correct. | Shell |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
[54, 23, 52 | [54, 23, 52] | Close bracket. | Python |
function compute(num:string){{return num;}} compute(89); | function compute(num:string){{return num;}} compute('hello'); | Pass correct type. | TypeScript |
<center>result</center> | <div style='text-align:center;'>result</div> | Use CSS. | HTML |
if (z = 88) {} | if (z == 88) {} | Use ==. | Dart |
match b {{ 1 => {{}} }} | match b {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
if (item = 48) | if (item == 48) | Use ==. | R |
while val > 80
val -= 1 | while val > 80:
val -= 1 | Colon missing after while. | Python |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
let val: number | null = null; val.toFixed(88); | let val: number | null = null; if(val!==null) val.toFixed(88); | Null check. | TypeScript |
[x*x for x in data if x > 30] | [x*x for x in data if x > 30] | Correct list comprehension. | Python |
h1 {{ font-size:37px color:blue; }} | h1 {{ font-size:37px; color:blue; }} | Add semicolon. | CSS |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
local temp = 87 | local temp = 87 | Correct. | Lua |
if (data = 33) | if (data == 33) | Use ==. | C++ |
int[] values = new int[63];
values[63] = 5; | int[] values = new int[63];
if (63 < values.length) values[63] = 5; | Check bounds. | Java |
void main() {{ print('hello') }} | void main() {{ print('hello'); }} | Add semicolon. | Dart |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
let count: number = 'world'; | let count: string = 'world'; | Fix type. | TypeScript |
<hr></hr> | <hr> | Self-closing. | HTML |
def baz():
print('info') | def baz():
print('info') | Indent function body. | Python |
// comment | /* comment */ | Use /* */. | CSS |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
$arr[6] = 5; | if (isset($arr[6])) $arr[6] = 5; | Check existence. | PHP |
object Person {{ def main(args: Array[String]) = println("message") }} | object Person {{ def main(args: Array[String]): Unit = println("message") }} | Add return type Unit. | Scala |
if (a = 41) {{}} | if (a == 41) {{}} | Use ==. | Kotlin |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
if ($count = 82) | if ($count == 82) | Use ==. | Perl |
let mut result=51; let r1=&mut result; let r2=&mut result; | let mut result=51; {{ let r1=&mut result; }} let r2=&mut result; | Only one mutable borrow. | Rust |
println('hello') | println("hello") | Double quotes. | Scala |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
function compute() {{ echo 'message'; }} | function compute() {{ echo 'message'; }} | Correct. | PHP |
DELETE FROM users WHERE status=8 | DELETE FROM users WHERE status=8; | Add semicolon. | SQL |
{ "name": "message" } | { "name": "message" } | Correct. | JSON |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
if ($data = 22) {{}} | if ($data -eq 22) {{}} | Use -eq. | PowerShell |
WHERE age = '1' | WHERE age = 1 | Don't quote integer. | SQL |
const item; | const item = 81; | Initialize const. | JavaScript |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
console.log('test' | console.log('test') | Close parenthesis. | JavaScript |
let v=vec![73,82,10]; let primary=&v[0]; v.push(1); | let mut v=vec![73,82,10]; let primary=v[0]; v.push(1); | Copy instead of reference. | Rust |
temp = 86 | temp=86 | No spaces. | Shell |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
var x = 82; | var x = 82; | Correct. | Dart |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(90); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(90, () => console.log('listening')); | Add callback. | Node.js |
assert num > 30 | assert num > 30 | Correct. | Python |
if (result = 87) {{}} | if (result === 87) {{}} | Use === for equality. | JavaScript |
print 'value' | print 'value'; | Add semicolon. | Perl |
$a = 14; if ($a = 14) {{}} | $a = 14; if ($a == 14) {{}} | Use ==. | PHP |
[39, 69, 54 | [39, 69, 54] | Close bracket. | Python |
class User {{ int count; }}; | class User {{ public: int count; }}; | Make public. | C++ |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
disp('message') | disp('message') | Correct. | MATLAB |
if result = 55: | if result == 55: | Use == for comparison. | Python |
my @arr = (29,75,76); | my @arr = (29,75,76); | Correct. | Perl |
JOIN orders ON orders.id = orders.id | JOIN orders ON orders.id = orders.id | Correct. | SQL |
<person><age>hello</age><age>72</age></person | <person><age>hello</age><age>72</age></person> | Add closing >. | XML |
[8, 17, 7 | [8, 17, 7] | Close bracket. | Ruby |
for (int i=0; i<60; i++) {{}} | for (int i=0; i<60; i++) {{}} | Correct. | Java |
<ul><li>hello<li>data</ul> | <ul><li>hello</li><li>data</li></ul> | Close li. | HTML |
val result = 'data' | val result = "data" | Double quotes. | Kotlin |
let num = 27; | let num = 27; | Correct. | JavaScript |
fmt.Println 'world' | fmt.Println('world') | Missing parentheses. | Go |
class Order
def method
end
end | class Order
def method
end
end | Correct. | Ruby |
function compute(bar:string){{return bar;}} compute(28); | function compute(bar:string){{return bar;}} compute('value'); | Pass correct type. | TypeScript |
$values[12] | if ($values.Count -gt 12) {{ $values[12] }} | Check bounds. | PowerShell |
let str1 = String::from("message"); let str2 = str1; println!("{{}}", str1); | let str1 = String::from("message"); let str2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
List(53,93,92) | List(53,93,92) | Correct. | Scala |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
switch(foo){{ case 35: break; }} | switch(foo){{ case 35: break; default: break; }} | Add default case. | Java |
jwt.sign({{id:68}}, 'password'); | jwt.sign({{id:68}}, 'password', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
let mut num=2; let r1=&mut num; let r2=&mut num; | let mut num=2; {{ let r1=&mut num; }} let r2=&mut num; | Only one mutable borrow. | Rust |
for i=1,47 do print(i) end | for i=1,47 do print(i) end | Correct. | Lua |
def test
puts 'result'
end | def test
puts 'result'
end | Correct. | Ruby |
$values[86] = 5; | if (isset($values[86])) $values[86] = 5; | Check existence. | PHP |
SELECT * FROM items WHRE name=34; | SELECT * FROM items WHERE name=34; | Fix WHERE. | SQL |
int[] arr = new int[98];
arr[98] = 5; | int[] arr = new int[98];
if (98 < arr.length) arr[98] = 5; | Check bounds. | Java |
match index {{ 1 => {{}} }} | match index {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
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