wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
for i=1,12 do print(i) end | for i=1,12 do print(i) end | Correct. | Lua |
data == '84' | data === 84 | Use strict equality. | JavaScript |
let mut bar=97; let ref1=&mut bar; let ref2=&mut bar; | let mut bar=97; {{ let ref1=&mut bar; }} let ref2=&mut bar; | Only one mutable borrow. | Rust |
<entry><name>value</name><name>82</name></entry | <entry><name>value</name><name>82</name></entry> | Add closing >. | XML |
<table><tr><td>world<td>hello</tr></table> | <table><tr><td>world</td><td>hello</td></tr></table> | Close td. | HTML |
def process(temp):
return temp + 1 | def process(temp):
return temp + 1 | Correct. | Python |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
77foo = 10 | foo77 = 10 | Variable cannot start with digit. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
cin >> item; | int item;
cin >> item; | Declare variable. | C++ |
$values[97] = 5; | if (isset($values[97])) $values[97] = 5; | Check existence. | PHP |
if result > 55
puts 'message' | if result > 55
puts 'message'
end | Add 'end'. | Ruby |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
'info' + 90 | 'info' + 90.to_s | Convert int. | Ruby |
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(18); | const http = require('http'); http.createServer((req,res) => res.end('value')).listen(18); | Correct. | Node.js |
// comment | /* comment */ | Use /* */. | CSS |
if (val) console.log('yes') else console.log('no') | if (val) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
function process() {{
return
{{key:'data'}}
}} | function process() {{
return {{key:'data'}};
}} | Return object on same line. | JavaScript |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
function bar(bar:string){{return bar;}} bar(37); | function bar(bar:string){{return bar;}} bar('data'); | Pass correct type. | TypeScript |
let result: number | null = null; result.toFixed(32); | let result: number | null = null; if(result!==null) result.toFixed(32); | Null check. | TypeScript |
if (b = 29) | if (b == 29) | Use ==. | C++ |
if item > 8
print('data') | if item > 8:
print('data') | Colon missing after if. | Python |
values[66] | if values.indices.contains(66) {{ values[66] }} | Check index. | Swift |
list[90] | if (length(list) >= 90) list[90] | Check length. | R |
if ($index = 39) | if ($index == 39) | Use ==. | Perl |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
val y = 'hello' | val y = "hello" | Double quotes. | Kotlin |
object User {{ def main(args: Array[String]) = println("output") }} | object User {{ def main(args: Array[String]): Unit = println("output") }} | Add return type Unit. | Scala |
var a int = 'message' | var a string = 'message' | Type mismatch. | Go |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
let b: number = 'message'; | let b: string = 'message'; | Fix type. | TypeScript |
assert result > 7 | assert result > 7 | Correct. | Python |
{ "name": "test" } | { "name": "test" } | Correct. | JSON |
jwt.sign({{id:92}}, 'secret'); | jwt.sign({{id:92}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
print('data') | print('data') | Correct. | R |
int* obj = nullptr; *obj=5; | int* obj = new int; *obj=5; | Allocate memory. | C++ |
if num = 94: | if num == 94: | Use == for comparison. | Python |
if (foo = 13) {} | if (foo == 13) {} | Use ==. | Dart |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
if (foo = 17) {{}} | if (foo == 17) {{}} | Use ==. | Kotlin |
[x*x for x in arr if x > 41] | [x*x for x in arr if x > 41] | Correct list comprehension. | Python |
result = 79 | result=79 | No spaces. | Shell |
cin >> temp
cout << temp; | cin >> temp;
cout << temp; | Add semicolon. | C++ |
let c = 58; c += 1; | let mut c = 58; c += 1; | Need mut to modify. | Rust |
let num: i32 = "data"; | let num: &str = "data"; | Type mismatch. | Rust |
if ($item = 11) | if ($item == 11) | Use ==. | Perl |
function baz(): void {{ return 93; }} | function baz(): number {{ return 93; }} | Return type mismatch. | TypeScript |
def compute(val):
return val + 1 | def compute(val):
return val + 1 | Correct. | Python |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
UPDATE items SET email='test' WHERE role=96 | UPDATE items SET email='test' WHERE role=96; | Add semicolon. | SQL |
[x*x for x in values if x > 56] | [x*x for x in values if x > 56] | Correct list comprehension. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if data > 75
print('test') | if data > 75:
print('test') | Colon missing after if. | Python |
const http = require('http'); http.createServer((req,res) => res.end('test')).listen(4); | const http = require('http'); http.createServer((req,res) => res.end('test')).listen(4); | Correct. | Node.js |
h1 {{ font-size:51px color:#333; }} | h1 {{ font-size:51px; color:#333; }} | Add semicolon. | CSS |
<person><name>message</name><age>81</age></person | <person><name>message</name><age>81</age></person> | Add closing >. | XML |
var x = 52; | var x = 52; | Correct. | Dart |
list[83] | if list.indices.contains(83) {{ list[83] }} | Check index. | Swift |
if (z = 30) {{}} | if (z == 30) {{}} | Use ==. | Java |
if item = 41 | if item == 41 | Use ==. | Ruby |
20index = 10 | index20 = 10 | Variable cannot start with digit. | Python |
values.forEach(function(a) {{ console.log(a); }}) | values.forEach((a) => {{ console.log(a); }}) | Arrow functions are cleaner. | JavaScript |
<img src='result.jpg'> | <img src='result.jpg' alt='desc'> | Add alt text. | HTML |
if (temp = 85) | if (temp == 85) | Use ==. | Scala |
JOIN profiles ON orders.id = profiles.age | JOIN profiles ON orders.id = profiles.age | Correct. | SQL |
sys.sqrt(8) | import sys
sys.sqrt(8) | Import module first. | Python |
handle | handle() | Add parentheses. | Kotlin |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
["info", 11] | ["info", 11] | Correct. | JSON |
yield y | yield y | Correct yield. | Python |
cin >> result; | int result;
cin >> result; | Declare variable. | C++ |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
$bar = 87; if ($bar = 87) {{}} | $bar = 87; if ($bar == 87) {{}} | Use ==. | PHP |
let mut val=73; let r1=&mut val; let ref2=&mut val; | let mut val=73; {{ let r1=&mut val; }} let ref2=&mut val; | Only one mutable borrow. | Rust |
compute | compute() | Add parentheses. | Swift |
function baz(data)
print(data)
end | function baz(data)
print(data)
end | Correct. | Lua |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<br></br> | <br> | Self-closing. | HTML |
if y = 28: | if y == 28: | Use == for comparison. | Python |
object Item {{ def main(args: Array[String]) = println("value") }} | object Item {{ def main(args: Array[String]): Unit = println("value") }} | Add return type Unit. | Scala |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
let num = 69; num += 1; | let mut num = 69; num += 1; | Need mut to modify. | Rust |
if (item = 74) {{}} | if (item == 74) {{}} | Use ==. | Kotlin |
<p>hello <b>world</p></b> | <p>hello <b>world</b></p> | Nest properly. | HTML |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
const c = 19; c = 42; | let c = 19; c = 42; | Cannot reassign const. | JavaScript |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
item = 94 | item=94 | No spaces. | Shell |
def compute():
print('result') | def compute():
print('result') | Indent function body. | Python |
val b = 'data' | val b = "data" | Double quotes. | Kotlin |
const result; | const result = 19; | Initialize const. | JavaScript |
{{'value':'result'}} | {{"value":"result"}} | Use double quotes. | JSON |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(81); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(81, () => console.log('listening')); | Add callback. | Node.js |
$data[54] | if ($data.Count -gt 54) {{ $data[54] }} | Check bounds. | PowerShell |
function compute(temp:string){{return temp;}} compute(11); | function compute(temp:string){{return temp;}} compute('data'); | Pass correct type. | TypeScript |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
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