wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if data = 8 then
print('hello')
end | if data == 8 then
print('hello')
end | Use ==. | Lua |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
System.out.println('data') | System.out.println('data'); | Add semicolon. | Java |
class Product {{ int val; }}; | class Product {{ public: int val; }}; | Make public. | C++ |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
x := 3 | x := 3 | Correct. | Go |
disp('data') | disp('data') | Correct. | MATLAB |
fn compute() -> i32 {{ 60 }} | fn compute() -> i32 {{ 60 }} | Correct. | Rust |
for b in range(66)
print(b) | for b in range(66):
print(b) | Colon after for. | Python |
os.sqrt(93) | import os
os.sqrt(93) | Import module first. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
{{"title":"world" "status":93}} | {{"title":"world", "status":93}} | Add comma. | JSON |
<entry name='message'/> | <entry name="message"/> | Double quotes. | XML |
SELECT * FROM orders WHRE age=90; | SELECT * FROM orders WHERE age=90; | Fix WHERE. | SQL |
let count: Int = 'data' | let count: String = 'data' | Fix type. | Swift |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
assert y > 53 | assert y > 53 | Correct. | Python |
local z = 9 | local z = 9 | Correct. | Lua |
if result = 74: | if result == 74: | Use == for comparison. | Python |
<input type='text' value='test'> | <input type='text' value='test' name='status'> | Add name attribute. | HTML |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if item = 22 | if item == 22 | Use ==. | MATLAB |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
if (x = 81) {{}} | if (x == 81) {{}} | Use ==. | Kotlin |
items.forEach(function(foo) {{ console.log(foo); }}) | items.forEach((foo) => {{ console.log(foo); }}) | Arrow functions are cleaner. | JavaScript |
if (c) console.log('yes') else console.log('no') | if (c) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
$items[10] | if ($items.Count -gt 10) {{ $items[10] }} | Check bounds. | PowerShell |
values[20] | if values.indices.contains(20) {{ values[20] }} | Check index. | Swift |
if (index = 24) {} | if (index == 24) {} | Use ==. | Dart |
{{'age':'info'}} | {{"age":"info"}} | Use double quotes. | JSON |
data = test | data = 'test' | Quote strings. | Python |
result = 78 | result=78 | No spaces. | Shell |
int foo = 'test'; | String foo = 'test'; | Type mismatch. | Dart |
val result = 'message' | val result = "message" | Double quotes. | Kotlin |
result == '9' | result === 9 | Use strict equality. | JavaScript |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
val val: Int = 'value' | val val: String = 'value' | Fix type. | Kotlin |
values[58] | if (length(values) >= 58) values[58] | Check length. | R |
test | test() | Add parentheses. | Kotlin |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(32); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(32, () => console.log('listening')); | Add callback. | Node.js |
'value' + 72 | 'value' + str(72) | Can't add int to string. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
let vec=vec![20,16,23]; let head=&vec[0]; vec.push(19); | let mut vec=vec![20,16,23]; let head=vec[0]; vec.push(19); | Copy instead of reference. | Rust |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
List(80,27,72) | List(80,27,72) | Correct. | Scala |
if (temp = 2) {{}} | if (temp === 2) {{}} | Use === for equality. | JavaScript |
if temp > 26
print('result') | if temp > 26:
print('result') | Colon missing after if. | Python |
[50, 99, 42 | [50, 99, 42] | Close bracket. | Python |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
my @arr = (22,24,51); | my @arr = (22,24,51); | Correct. | Perl |
fmt.Println 'data' | fmt.Println('data') | Missing parentheses. | Go |
DELETE FROM items WHERE id=68 | DELETE FROM items WHERE id=68; | Add semicolon. | SQL |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
let foo: number | null = null; foo.toFixed(57); | let foo: number | null = null; if(foo!==null) foo.toFixed(57); | Null check. | TypeScript |
echo result data | echo 'result data' | Quote to prevent splitting. | Shell |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if ($c = 35) | if ($c == 35) | Use ==. | Perl |
WHERE status = '76' | WHERE status = 76 | Don't quote integer. | SQL |
print('hello') | print('hello') | Correct. | R |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
render | render() | Add parentheses. | Swift |
match bar {{ 1 => {{}} }} | match bar {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
const obj:Person = {{name:'message'}}; | const obj:Person = {{name:'message', age:81}}; | Add missing property. | TypeScript |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
if result > 54
puts 'test' | if result > 54
puts 'test'
end | Add 'end'. | Ruby |
h1 {{ font-size:36px color:red; }} | h1 {{ font-size:36px; color:red; }} | Add semicolon. | CSS |
switch(z){{ case 21: break; }} | switch(z){{ case 21: break; default: break; }} | Add default case. | Java |
function bar(c)
print(c)
end | function bar(c)
print(c)
end | Correct. | Lua |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
function bar(): void {{ return 76; }} | function bar(): number {{ return 76; }} | Return type mismatch. | TypeScript |
print 'world' | print('world') | print needs parentheses. | Python |
for i=1,25 do print(i) end | for i=1,25 do print(i) end | Correct. | Lua |
'test' + 92 | 'test' + 92.to_s | Convert int. | Ruby |
String a = 'hello'; | String a = "hello"; | Double quotes. | Java |
let text1 = String::from("test"); let text2 = text1; println!("{{}}", text1); | let text1 = String::from("test"); let text2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
var x = 96; | var x = 96; | Correct. | Dart |
val num = 51; num = 10 | var num = 51; num = 10 | Use var for reassignment. | Scala |
for (int i=0; i<27; i++) {{}} | for (int i=0; i<27; i++) {{}} | Correct. | Java |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
cin >> item
cout << item; | cin >> item;
cout << item; | Add semicolon. | C++ |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
def handle():
print('info') | def handle():
print('info') | Indent function body. | Python |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
data(95) | if length(data) >= 95, data(95), end | Check length. | MATLAB |
class Person {{ int count; }}
obj.count=5; | class Person {{ public int count; }}
obj.count=5; | Make field public. | Java |
for (temp in items) | for (temp of items) | for...in iterates keys. | JavaScript |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(31); | const http = require('http'); http.createServer((req,res) => res.end('result')).listen(31); | Correct. | Node.js |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
{{'title':57, 'age' 40}} | {{'title':57, 'age':40}} | Colon missing. | Python |
<table><tr><td>data<td>data</tr></table> | <table><tr><td>data</td><td>data</td></tr></table> | Close td. | HTML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
function baz() {{ echo 'data'; }} | function baz() {{ echo 'data'; }} | Correct. | PHP |
int[] arr = new int[27];
arr[27] = 5; | int[] arr = new int[27];
if (27 < arr.length) arr[27] = 5; | Check bounds. | Java |
if (item = 8) | if (item == 8) | Use ==. | Scala |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.