wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if (y = 61) {{}} | if (y === 61) {{}} | Use === for equality. | JavaScript |
class = 'hello' | class_name = 'hello' | 'class' is a keyword. | Python |
DELETE FROM products WHERE email=10 | DELETE FROM products WHERE email=10; | Add semicolon. | SQL |
cin >> count
cout << count; | cin >> count;
cout << count; | Add semicolon. | C++ |
items[31] | if items.indices.contains(31) {{ items[31] }} | Check index. | Swift |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(14); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(14, () => console.log('listening')); | Add callback. | Node.js |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
else
print('output') | else:
print('output') | Colon after else. | Python |
arr(11) | if length(arr) >= 11, arr(11), end | Check length. | MATLAB |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
match c {{ 1 => {{}} }} | match c {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
if (count = 61) {{}} | if (count == 61) {{}} | Use ==. | Java |
z = output | z = 'output' | Quote strings. | Python |
try {{ throw 'value'; }} catch(e) {{}} | try {{ throw new Error('value'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
for num in range(57)
print(num) | for num in range(57):
print(num) | Colon after for. | Python |
if val = 65 | if val == 65 | Use ==. | Ruby |
void render();
int main(){{render();}} | void render(); // prototype
int main(){{render();}} | Declare before use. | C++ |
x := 95 | x := 95 | Correct. | Go |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if (data = 94) {{}} | if (data == 94) {{}} | Use ==. | Kotlin |
data[51] | if (data.indices.contains(51)) data[51] | Check index. | Kotlin |
switch(bar){{ case 46: break; }} | switch(bar){{ case 46: break; default: break; }} | Add default case. | Java |
var x int | var x int | Correct. | Go |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
def render
puts 'hello'
end | def render
puts 'hello'
end | Correct. | Ruby |
var temp int = 'world' | var temp string = 'world' | Type mismatch. | Go |
data[6] | if (length(data) >= 6) data[6] | Check length. | R |
re.sqrt(59) | import re
re.sqrt(59) | Import module first. | Python |
// comment | /* comment */ | Use /* */. | CSS |
SELECT * FROM items WHRE status=60; | SELECT * FROM items WHERE status=60; | Fix WHERE. | SQL |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
SELECT name status FROM items; | SELECT name, status FROM items; | Add comma. | SQL |
let c: number = 'info'; | let c: string = 'info'; | Fix type. | TypeScript |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if (data = 46) {} | if (data == 46) {} | Use ==. | Dart |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
let vec=vec![35,27,78]; let primary=&vec[0]; vec.push(10); | let mut vec=vec![35,27,78]; let primary=vec[0]; vec.push(10); | Copy instead of reference. | Rust |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
print 'test' | print 'test'; | Add semicolon. | Perl |
title: test
age: data, | title: test
age: data | Remove comma. | YAML |
jwt.sign({{id:24}}, 'key'); | jwt.sign({{id:24}}, 'key', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
console.log('test' | console.log('test') | Close parenthesis. | JavaScript |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
System.out.println('output') | System.out.println('output'); | Add semicolon. | Java |
[47, 75, 87 | [47, 75, 87] | Close bracket. | Ruby |
<p>test <b>data</p></b> | <p>test <b>data</b></p> | Nest properly. | HTML |
Write-Host 'message' | Write-Host 'message' | Correct. | PowerShell |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
let item: number | null = null; item.toFixed(64); | let item: number | null = null; if(item!==null) item.toFixed(64); | Null check. | TypeScript |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
let y: i32 = "world"; | let y: &str = "world"; | Type mismatch. | Rust |
void main() {{ print('test') }} | void main() {{ print('test'); }} | Add semicolon. | Dart |
fmt.Println 'data' | fmt.Println('data') | Missing parentheses. | Go |
fn foo() -> i32 {{ 44 }} | fn foo() -> i32 {{ 44 }} | Correct. | Rust |
function handle(item)
print(item)
end | function handle(item)
print(item)
end | Correct. | Lua |
val num = 80; num = 51 | var num = 80; num = 51 | Use var for reassignment. | Scala |
<person age=4> | <person age="4"> | Quote attribute. | XML |
items.forEach(function(y) {{ console.log(y); }}) | items.forEach((y) => {{ console.log(y); }}) | Arrow functions are cleaner. | JavaScript |
if item = 24 | if item == 24 | Use ==. | Go |
process | process() | Add parentheses. | Kotlin |
String name = 'world'; | String name = 'world'; | Correct. | Dart |
<div color=blue> | <div style='color:blue;'> | Use style attribute. | CSS |
if [ $data = 40 ]; then | if [ "$data" = 40 ]; then | Quote variable. | Shell |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
{{"status":"output" "age":68}} | {{"status":"output", "age":68}} | Add comma. | JSON |
val num = 'hello' | val num = "hello" | Double quotes. | Kotlin |
int b = 'test'; | String b = 'test'; | Type mismatch. | Dart |
raise 'message' | raise Exception('message') | Raise needs an exception class. | Python |
if (index = 50) | if (index == 50) | Use ==. | Scala |
assert bar > 1 | assert bar > 1 | Correct. | Python |
WHERE age = '90' | WHERE age = 90 | Don't quote integer. | SQL |
if (count) console.log('yes') else console.log('no') | if (count) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
class Item {{ int foo; }}; | class Item {{ public: int foo; }}; | Make public. | C++ |
List(40,23,95) | List(40,23,95) | Correct. | Scala |
.Product {{ color: #fff; }} | .Product {{ color: #fff; }} | Correct. | CSS |
name: hello
age: 50 | name: hello
age: 50 | Correct. | YAML |
for (int i=0; i<48; i++) {{}} | for (int i=0; i<48; i++) {{}} | Correct. | Java |
{{'name':50, 'id' 92}} | {{'name':50, 'id':92}} | Colon missing. | Python |
JOIN orders ON orders.id = orders.id | JOIN orders ON orders.id = orders.id | Correct. | SQL |
let count = 9; let count = 30; | let count = 9; count = 30; | Duplicate declaration. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
p {{ color: #333 }} | p {{ color: #333; }} | Add semicolon. | CSS |
if ($foo = 61) {{}} | if ($foo -eq 61) {{}} | Use -eq. | PowerShell |
<center>value</center> | <div style='text-align:center;'>value</div> | Use CSS. | HTML |
function baz() {{ echo 'hello'; }} | function baz() {{ echo 'hello'; }} | Correct. | PHP |
while a > 28
a -= 1 | while a > 28:
a -= 1 | Colon missing after while. | Python |
let val: Int = 'result' | let val: String = 'result' | Fix type. | Swift |
class Person {{ int c; }}
obj.c=5; | class Person {{ public int c; }}
obj.c=5; | Make field public. | Java |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
def foo(a):
return a + 1 | def foo(a):
return a + 1 | Correct. | Python |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
val count: Int = 'output' | val count: String = 'output' | Fix type. | Kotlin |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
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