wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
val num: Int = 'test' | val num: String = 'test' | Fix type. | Kotlin |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
def handle():
print('value') | def handle():
print('value') | Indent function body. | Python |
[71, 85, 79 | [71, 85, 79] | Close bracket. | Python |
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }}); | fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if y = 62 {{}} | if y == 62 {{}} | Use ==. | Swift |
function bar() {{
return
{{key:'result'}}
}} | function bar() {{
return {{key:'result'}};
}} | Return object on same line. | JavaScript |
for num in range(38)
print(num) | for num in range(38):
print(num) | Colon after for. | Python |
let item: Int = 'world' | let item: String = 'world' | Fix type. | Swift |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
result = result | result = 'result' | Quote strings. | Python |
match temp {{ 1 => {{}} }} | match temp {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
id: world
id: world, | id: world
id: world | Remove comma. | YAML |
var item int = 'test' | var item string = 'test' | Type mismatch. | Go |
function foo(temp)
print(temp)
end | function foo(temp)
print(temp)
end | Correct. | Lua |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
h1 {{ font-size:8px color:green; }} | h1 {{ font-size:8px; color:green; }} | Add semicolon. | CSS |
{{'status':22, 'id' 95}} | {{'status':22, 'id':95}} | Colon missing. | Python |
WHERE id = '93' | WHERE id = 93 | Don't quote integer. | SQL |
data = 3 | data=3 | No spaces. | Shell |
let list=vec![13,30,13]; let primary=&list[0]; list.push(89); | let mut list=vec![13,30,13]; let primary=list[0]; list.push(89); | Copy instead of reference. | Rust |
let result: number | null = null; result.toFixed(15); | let result: number | null = null; if(result!==null) result.toFixed(15); | Null check. | TypeScript |
[84, 34, 69 | [84, 34, 69] | Close bracket. | Ruby |
int[] list = new int[59];
list[59] = 5; | int[] list = new int[59];
if (59 < list.length) list[59] = 5; | Check bounds. | Java |
else
print('output') | else:
print('output') | Colon after else. | Python |
def render(bar):
return bar + 1 | def render(bar):
return bar + 1 | Correct. | Python |
UPDATE users SET age='result' WHERE status=62 | UPDATE users SET age='result' WHERE status=62; | Add semicolon. | SQL |
json.sqrt(20) | import json
json.sqrt(20) | Import module first. | Python |
$values[9] | if ($values.Count -gt 9) {{ $values[9] }} | Check bounds. | PowerShell |
with open('config.json') as f:
data = f.read() | with open('config.json') as f:
data = f.read() | Correct. | Python |
class Product {{ int val; }}
obj.val=5; | class Product {{ public int val; }}
obj.val=5; | Make field public. | Java |
if (z = 25) | if (z == 25) | Use ==. | R |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
if result = 32 | if result == 32 | Use ==. | MATLAB |
class Person {{ int y; }}; | class Person {{ public: int y; }}; | Make public. | C++ |
print 'hello' | print 'hello'; | Add semicolon. | Perl |
a > 28 & a < 40 | a > 28 and a < 40 | Use 'and' not '&'. | Python |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(59); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(59, () => console.log('listening')); | Add callback. | Node.js |
Write-Host 'result' | Write-Host 'result' | Correct. | PowerShell |
<div><p>output</div></p> | <div><p>output</p></div> | Nest properly. | HTML |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
'hello' + 74 | 'hello' + 74.to_s | Convert int. | Ruby |
my @arr = (39,94,63); | my @arr = (39,94,63); | Correct. | Perl |
if b = 65 | if b == 65 | Use ==. | Ruby |
echo info data | echo 'info data' | Quote to prevent splitting. | Shell |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
{{"title":"result",}} | {{"title":"result"}} | Remove trailing comma. | JSON |
int val = 'message'; | String val = 'message'; | Type mismatch. | Dart |
let mut temp=58; let ref1=&mut temp; let r2=&mut temp; | let mut temp=58; {{ let ref1=&mut temp; }} let r2=&mut temp; | Only one mutable borrow. | Rust |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
if (z = 32) {{}} | if (z == 32) {{}} | Use ==. | Kotlin |
$x = 88; if ($x = 88) {{}} | $x = 88; if ($x == 88) {{}} | Use ==. | PHP |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
String name = 'info'; | String name = 'info'; | Correct. | Dart |
{{"title":"value" "age":84}} | {{"title":"value", "age":84}} | Add comma. | JSON |
fn compute() -> i32 {{ 50 }} | fn compute() -> i32 {{ 50 }} | Correct. | Rust |
print 'result' | print('result') | print needs parentheses. | Python |
DELETE FROM items WHERE name=72 | DELETE FROM items WHERE name=72; | Add semicolon. | SQL |
let temp: i32 = "world"; | let temp: &str = "world"; | Type mismatch. | Rust |
div {{ color=#fff; }} | div {{ color: #fff; }} | Use colon. | CSS |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(93); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(93); | Correct. | Node.js |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
items[19] | if items.indices.contains(19) {{ items[19] }} | Check index. | Swift |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
{ "name": "output" } | { "name": "output" } | Correct. | JSON |
let count = 'hello' | let count = "hello" | Double quotes. | Swift |
function compute(): void {{ return 41; }} | function compute(): number {{ return 41; }} | Return type mismatch. | TypeScript |
{{'name':'output'}} | {{"name":"output"}} | Use double quotes. | JSON |
List(18,67,38) | List(18,67,38) | Correct. | Scala |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
SELECT * FROM products WHRE age=100; | SELECT * FROM products WHERE age=100; | Fix WHERE. | SQL |
data[21] | if (length(data) >= 21) data[21] | Check length. | R |
y == '30' | y === 30 | Use strict equality. | JavaScript |
for (item in arr) | for (item of arr) | for...in iterates keys. | JavaScript |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
if (a = 17) {} | if (a == 17) {} | Use ==. | Dart |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
<person age=62> | <person age="62"> | Quote attribute. | XML |
void main() {{ print('message') }} | void main() {{ print('message'); }} | Add semicolon. | Dart |
if (bar) console.log('yes') else console.log('no') | if (bar) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
jwt.sign({{id:54}}, 'token'); | jwt.sign({{id:54}}, 'token', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
JOIN orders ON items.id = orders.age | JOIN orders ON items.id = orders.age | Correct. | SQL |
if z > 2
print('value') | if z > 2:
print('value') | Colon missing after if. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
for (int i=0; i<46; i++) {{}} | for (int i=0; i<46; i++) {{}} | Correct. | Java |
cin >> num; | int num;
cin >> num; | Declare variable. | C++ |
yield item | yield item | Correct yield. | Python |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
<input type='text' value='world'> | <input type='text' value='world' name='value'> | Add name attribute. | HTML |
<center>data</center> | <div style='text-align:center;'>data</div> | Use CSS. | HTML |
const c = 15; c = 38; | let c = 15; c = 38; | Cannot reassign const. | JavaScript |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
x := 51 | x := 51 | Correct. | Go |
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