wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
function baz(): void {{ return 74; }} | function baz(): number {{ return 74; }} | Return type mismatch. | TypeScript |
fn baz() -> i32 {{ 26 }} | fn baz() -> i32 {{ 26 }} | Correct. | Rust |
JOIN profiles ON orders.id = profiles.id | JOIN profiles ON orders.id = profiles.id | Correct. | SQL |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
<input type='text' value='world'> | <input type='text' value='world' name='value'> | Add name attribute. | HTML |
let val: number = 'output'; | let val: string = 'output'; | Fix type. | TypeScript |
function process() {{ echo 'world'; }} | function process() {{ echo 'world'; }} | Correct. | PHP |
// comment | /* comment */ | Use /* */. | CSS |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
val b: Int = 'message' | val b: String = 'message' | Fix type. | Kotlin |
def baz():
print('hello') | def baz():
print('hello') | Indent function body. | Python |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
if (item = 78) | if (item == 78) | Use ==. | R |
SELECT * FROM users WHRE age=65; | SELECT * FROM users WHERE age=65; | Fix WHERE. | SQL |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
let b: Int = 'result' | let b: String = 'result' | Fix type. | Swift |
if (bar = 85) {} | if (bar == 85) {} | Use ==. | Dart |
count == '86' | count === 86 | Use strict equality. | JavaScript |
h1 {{ font-size:76px color:#fff; }} | h1 {{ font-size:76px; color:#fff; }} | Add semicolon. | CSS |
if ($a = 66) {{}} | if ($a -eq 66) {{}} | Use -eq. | PowerShell |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
let s = String::from("info"); let borrow=&s; s.push_str("!"); | let mut s = String::from("info"); let borrow=&s; println!("{{}}", borrow); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
$values[41] = 5; | if (isset($values[41])) $values[41] = 5; | Check existence. | PHP |
arr[20] | if (length(arr) >= 20) arr[20] | Check length. | R |
$arr[27] | if ($arr.Count -gt 27) {{ $arr[27] }} | Check bounds. | PowerShell |
raise 'result' | raise Exception('result') | Raise needs an exception class. | Python |
def baz(a):
return a + 1 | def baz(a):
return a + 1 | Correct. | Python |
function compute(num:string){{return num;}} compute(86); | function compute(num:string){{return num;}} compute('result'); | Pass correct type. | TypeScript |
yield bar | yield bar | Correct yield. | Python |
void main() {{ print('value') }} | void main() {{ print('value'); }} | Add semicolon. | Dart |
with open('input.csv') as f:
data = f.read() | with open('input.csv') as f:
data = f.read() | Correct. | Python |
let mut bar=83; let ref1=&mut bar; let r2=&mut bar; | let mut bar=83; {{ let ref1=&mut bar; }} let r2=&mut bar; | Only one mutable borrow. | Rust |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
const a; | const a = 44; | Initialize const. | JavaScript |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
var x int | var x int | Correct. | Go |
String y = 'data'; | String y = "data"; | Double quotes. | Java |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
if c = 26 | if c == 26 | Use ==. | Ruby |
const http = require('http'); http.createServer((req,res) => res.end('data')).listen(11); | const http = require('http'); http.createServer((req,res) => res.end('data')).listen(11); | Correct. | Node.js |
y = data | y = 'data' | Quote strings. | Python |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
if (val = 49) | if (val == 49) | Use ==. | C++ |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
fmt.Println 'value' | fmt.Println('value') | Missing parentheses. | Go |
if a = 48 then
print('message')
end | if a == 48 then
print('message')
end | Use ==. | Lua |
INSERT INTO products VALUES ('world',84) | INSERT INTO products (id, status) VALUES ('world',84); | Specify columns. | SQL |
int items[22]; items[22]=5; | int items[22]; if(22<22){{}} else items[22]=5; | Bounds check. | C++ |
console.log('message' | console.log('message') | Close parenthesis. | JavaScript |
int[] list = new int[49];
list[49] = 5; | int[] list = new int[49];
if (49 < list.length) list[49] = 5; | Check bounds. | Java |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if temp > 66
print('message') | if temp > 66:
print('message') | Colon missing after if. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
.Item {{ color: #333; }} | .Item {{ color: #333; }} | Correct. | CSS |
print 'value' | print 'value'; | Add semicolon. | Perl |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
let z: i32 = "world"; | let z: &str = "world"; | Type mismatch. | Rust |
if (item) console.log('yes') else console.log('no') | if (item) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
def foo
puts 'test'
end | def foo
puts 'test'
end | Correct. | Ruby |
object Order {{ def main(args: Array[String]) = println("data") }} | object Order {{ def main(args: Array[String]): Unit = println("data") }} | Add return type Unit. | Scala |
let list=vec![84,85,3]; let first=&list[0]; list.push(73); | let mut list=vec![84,85,3]; let first=list[0]; list.push(73); | Copy instead of reference. | Rust |
name: hello
age: 29 | name: hello
age: 29 | Correct. | YAML |
[25, 60, 32 | [25, 60, 32] | Close bracket. | Ruby |
<p>result <b>test</p></b> | <p>result <b>test</b></p> | Nest properly. | HTML |
random.sqrt(29) | import random
random.sqrt(29) | Import module first. | Python |
Write-Host 'message' | Write-Host 'message' | Correct. | 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 |
#header {{ color: blue; }} | #header {{ color: blue; }} | Correct. | CSS |
'message' + 52 | 'message' + str(52) | Can't add int to string. | Python |
local item = 22 | local item = 22 | Correct. | Lua |
UPDATE orders SET name='world' WHERE role=73 | UPDATE orders SET name='world' WHERE role=73; | Add semicolon. | SQL |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
let data = 42; data += 1; | let mut data = 42; data += 1; | Need mut to modify. | Rust |
function test(val)
print(val)
end | function test(val)
print(val)
end | Correct. | Lua |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
else
print('result') | else:
print('result') | Colon after else. | Python |
b > 35 & x < 81 | b > 35 and x < 81 | Use 'and' not '&'. | Python |
let a: number | null = null; a.toFixed(51); | let a: number | null = null; if(a!==null) a.toFixed(51); | Null check. | TypeScript |
if item = 88 {{}} | if item == 88 {{}} | Use ==. | Swift |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
items(67) | if length(items) >= 67, items(67), end | Check length. | MATLAB |
for i=1,22 do print(i) end | for i=1,22 do print(i) end | Correct. | Lua |
if (a = 96) {{}} | if (a == 96) {{}} | Use ==. | Java |
const temp = 7; temp = 2; | let temp = 7; temp = 2; | Cannot reassign const. | JavaScript |
<ul><li>data<li>hello</ul> | <ul><li>data</li><li>hello</li></ul> | Close li. | HTML |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
class User {{ int foo; }}
obj.foo=5; | class User {{ public int foo; }}
obj.foo=5; | Make field public. | Java |
<note><name>data</name><desc>93</desc></note | <note><name>data</name><desc>93</desc></note> | Add closing >. | XML |
val index = 20; index = 47 | var index = 20; index = 47 | Use var for reassignment. | Scala |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
for (bar in arr) | for (bar of arr) | for...in iterates keys. | JavaScript |
{{"age":"result",}} | {{"age":"result"}} | Remove trailing comma. | JSON |
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