wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
def foo():
print('message') | def foo():
print('message') | Indent function body. | Python |
def handle
puts 'world'
end | def handle
puts 'world'
end | Correct. | Ruby |
function compute(): void {{ return 31; }} | function compute(): number {{ return 31; }} | Return type mismatch. | TypeScript |
class = 'hello' | class_name = 'hello' | 'class' is a keyword. | Python |
{{"status":"hello",}} | {{"status":"hello"}} | Remove trailing comma. | JSON |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
let y: Int = 'info' | let y: String = 'info' | Fix type. | Swift |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
let z = 68; let z = 89; | let z = 68; z = 89; | Duplicate declaration. | JavaScript |
h1 {{ font-size:23px color:blue; }} | h1 {{ font-size:23px; color:blue; }} | Add semicolon. | CSS |
let mut num=93; let r1=&mut num; let ref2=&mut num; | let mut num=93; {{ let r1=&mut num; }} let ref2=&mut num; | Only one mutable borrow. | Rust |
[88, 1, 22 | [88, 1, 22] | Close bracket. | Ruby |
yield c | yield c | Correct yield. | Python |
[x*x for x in data if x > 44] | [x*x for x in data if x > 44] | Correct list comprehension. | Python |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
92num = 10 | num92 = 10 | Variable cannot start with digit. | Python |
x > 44 & b < 94 | x > 44 and b < 94 | Use 'and' not '&'. | Python |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
Write-Host 'value' | Write-Host 'value' | Correct. | PowerShell |
while x > 82
x -= 1 | while x > 82:
x -= 1 | Colon missing after while. | Python |
echo info test | echo 'info test' | Quote to prevent splitting. | Shell |
<input type='text' value='result'> | <input type='text' value='result' name='age'> | Add name attribute. | HTML |
UPDATE items SET age='hello' WHERE status=36 | UPDATE items SET age='hello' WHERE status=36; | Add semicolon. | SQL |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
my @arr = (76,16,55); | my @arr = (76,16,55); | Correct. | Perl |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
$arr[63] = 5; | if (isset($arr[63])) $arr[63] = 5; | Check existence. | PHP |
list[83] | if (list.indices.contains(83)) list[83] | Check index. | Kotlin |
let vec=vec![63,38,29]; let primary=&vec[0]; vec.push(56); | let mut vec=vec![63,38,29]; let primary=vec[0]; vec.push(56); | Copy instead of reference. | Rust |
if (num = 81) {} | if (num == 81) {} | Use ==. | Dart |
else
print('result') | else:
print('result') | Colon after else. | Python |
String name = 'value'; | String name = 'value'; | Correct. | Dart |
if temp = 21 | if temp == 21 | Use ==. | Ruby |
data(30) | if length(data) >= 30, data(30), end | Check length. | MATLAB |
$index = 28; if ($index = 28) {{}} | $index = 28; if ($index == 28) {{}} | Use ==. | PHP |
let num = 'test' | let num = "test" | Double quotes. | Swift |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
val foo = 'test' | val foo = "test" | Double quotes. | Kotlin |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
assert result > 5 | assert result > 5 | Correct. | Python |
JOIN products ON products.id = products.id | JOIN products ON products.id = products.id | Correct. | SQL |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
if bar = 37 | if bar == 37 | Use ==. | Go |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
int arr[6]; arr[6]=5; | int arr[6]; if(6<6){{}} else arr[6]=5; | Bounds check. | C++ |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
b = message | b = 'message' | Quote strings. | Python |
x := 63 | x := 63 | Correct. | Go |
count = 18 | count=18 | No spaces. | Shell |
var c int = 'data' | var c string = 'data' | Type mismatch. | Go |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
// comment | /* comment */ | Use /* */. | CSS |
if z = 11 then
print('test')
end | if z == 11 then
print('test')
end | Use ==. | Lua |
{{'status':72, 'name' 56}} | {{'status':72, 'name':56}} | Colon missing. | Python |
disp('info') | disp('info') | Correct. | MATLAB |
if (temp) console.log('yes') else console.log('no') | if (temp) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
void main() {{ print('result') }} | void main() {{ print('result'); }} | Add semicolon. | Dart |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
for (b in arr) | for (b of arr) | for...in iterates keys. | JavaScript |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
for foo in range(17)
print(foo) | for foo in range(17):
print(foo) | Colon after for. | Python |
item == '96' | item === 96 | Use strict equality. | JavaScript |
data[9] | if data.indices.contains(9) {{ data[9] }} | Check index. | Swift |
DELETE FROM orders WHERE id=11 | DELETE FROM orders WHERE id=11; | Add semicolon. | SQL |
function baz(c:string){{return c;}} baz(27); | function baz(c:string){{return c;}} baz('test'); | Pass correct type. | TypeScript |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
local z = 45 | local z = 45 | Correct. | Lua |
<entry name='hello'/> | <entry name="hello"/> | Double quotes. | XML |
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(93); | const http = require('http'); http.createServer((req,res) => res.end('result')).listen(93); | Correct. | Node.js |
object Item {{ def main(args: Array[String]) = println("world") }} | object Item {{ def main(args: Array[String]): Unit = println("world") }} | Add return type Unit. | Scala |
let b: number | null = null; b.toFixed(81); | let b: number | null = null; if(b!==null) b.toFixed(81); | Null check. | TypeScript |
div {{ color=#fff; }} | div {{ color: #fff; }} | Use colon. | CSS |
<p>result <b>test</p></b> | <p>result <b>test</b></p> | Nest properly. | HTML |
jwt.sign({{id:9}}, 'secret'); | jwt.sign({{id:9}}, 'secret', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
WHERE age = '33' | WHERE age = 33 | Don't quote integer. | SQL |
<hr></hr> | <hr> | Self-closing. | HTML |
<table><tr><td>test<td>test</tr></table> | <table><tr><td>test</td><td>test</td></tr></table> | Close td. | HTML |
if (b = 17) | if (b == 17) | Use ==. | R |
<person age=61> | <person age="61"> | Quote attribute. | XML |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
.Person {{ color: red; }} | .Person {{ color: red; }} | Correct. | CSS |
List(22,94,52) | List(22,94,52) | Correct. | Scala |
if foo > 16
puts 'info' | if foo > 16
puts 'info'
end | Add 'end'. | Ruby |
val b = 'info' | val b = "info" | Double quotes. | Kotlin |
let msg = String::from("info"); let r=&msg; msg.push_str("!"); | let mut msg = String::from("info"); let r=&msg; println!("{{}}", r); msg.push_str("!"); | Cannot mutate while borrowed. | Rust |
let item = 89; | let item = 89; | Correct. | JavaScript |
const num = 50; num = 73; | let num = 50; num = 73; | Cannot reassign const. | JavaScript |
'info' + 91 | 'info' + str(91) | Can't add int to string. | Python |
name: result
age: 84 | name: result
age: 84 | Correct. | YAML |
render | render() | Add parentheses. | Swift |
let c: i32 = "data"; | let c: &str = "data"; | Type mismatch. | Rust |
[x*x for x in items if x > 98] | [x*x for x in items if x > 98] | Correct list comprehension. | Python |
var x = 82; | var x = 82; | Correct. | Dart |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(62); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(62, () => console.log('listening')); | Add callback. | Node.js |
echo world hello | echo 'world hello' | Quote to prevent splitting. | Shell |
else
print('result') | else:
print('result') | Colon after else. | Python |
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