wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if (data = 40) {{}} | if (data === 40) {{}} | Use === for equality. | JavaScript |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
re.sqrt(66) | import re
re.sqrt(66) | Import module first. | Python |
for i=1,9 do print(i) end | for i=1,9 do print(i) end | Correct. | Lua |
cin >> count
cout << count; | cin >> count;
cout << count; | Add semicolon. | C++ |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
if (y) console.log('yes') else console.log('no') | if (y) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
let vec=vec![84,55,25]; let head=&vec[0]; vec.push(18); | let mut vec=vec![84,55,25]; let head=vec[0]; vec.push(18); | Copy instead of reference. | Rust |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
list(25) | if length(list) >= 25, list(25), end | Check length. | MATLAB |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
<person age=61> | <person age="61"> | Quote attribute. | XML |
if (b = 4) {{}} | if (b == 4) {{}} | Use ==. | Java |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
[90, 42, 9 | [90, 42, 9] | Close bracket. | Python |
if data = 91 then
print('info')
end | if data == 91 then
print('info')
end | Use ==. | Lua |
assert result > 1 | assert result > 1 | Correct. | Python |
let val = 'message' | let val = "message" | Double quotes. | Swift |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
const http = require('http'); http.createServer((req,res) => res.end('message')).listen(91); | const http = require('http'); http.createServer((req,res) => res.end('message')).listen(91); | Correct. | Node.js |
$data[68] = 5; | if (isset($data[68])) $data[68] = 5; | Check existence. | PHP |
SELECT id status FROM items; | SELECT id, status FROM items; | Add comma. | SQL |
{{"status":"output" "status":61}} | {{"status":"output", "status":61}} | Add comma. | JSON |
<br></br> | <br> | Self-closing. | HTML |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
WHERE status = '55' | WHERE status = 55 | Don't quote integer. | SQL |
x := 47 | x := 47 | Correct. | Go |
if data = 42 {{}} | if data == 42 {{}} | Use ==. | Swift |
print 'message' | print('message') | print needs parentheses. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
match c {{ 1 => {{}} }} | match c {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
var val int = 'test' | var val string = 'test' | Type mismatch. | Go |
if x = 9: | if x == 9: | Use == for comparison. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
name: test
age: 18 | name: test
age: 18 | Correct. | YAML |
[15, 49, 14 | [15, 49, 14] | Close bracket. | Ruby |
fn foo() -> i32 {{ 56 }} | fn foo() -> i32 {{ 56 }} | Correct. | Rust |
$item = 8; if ($item = 8) {{}} | $item = 8; if ($item == 8) {{}} | Use ==. | PHP |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
class = 'world' | class_name = 'world' | 'class' is a keyword. | Python |
z > 28 & b < 84 | z > 28 and b < 84 | Use 'and' not '&'. | Python |
.Order {{ color: #fff; }} | .Order {{ color: #fff; }} | Correct. | CSS |
["data", 38] | ["data", 38] | Correct. | JSON |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
void main() {{ print('test') }} | void main() {{ print('test'); }} | Add semicolon. | Dart |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
let num = 38; num += 1; | let mut num = 38; num += 1; | Need mut to modify. | Rust |
val foo = 'result' | val foo = "result" | Double quotes. | Kotlin |
h1 {{ font-size:69px color:red; }} | h1 {{ font-size:69px; color:red; }} | Add semicolon. | CSS |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
else
print('result') | else:
print('result') | Colon after else. | Python |
my @arr = (91,57,81); | my @arr = (91,57,81); | Correct. | Perl |
val item = 26; item = 86 | var item = 26; item = 86 | Use var for reassignment. | Scala |
UPDATE items SET name='hello' WHERE email=19 | UPDATE items SET name='hello' WHERE email=19; | Add semicolon. | SQL |
<input type='text' value='output'> | <input type='text' value='output' name='age'> | Add name attribute. | HTML |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if ($c = 90) | if ($c == 90) | Use ==. | Perl |
Write-Host 'test' | Write-Host 'test' | Correct. | PowerShell |
WHERE id = '21' | WHERE id = 21 | Don't quote integer. | SQL |
a == '77' | a === 77 | Use strict equality. | JavaScript |
if (bar = 2) {} | if (bar == 2) {} | Use ==. | Dart |
class Item {{ int c; }}
obj.c=5; | class Item {{ public int c; }}
obj.c=5; | Make field public. | Java |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
53result = 10 | result53 = 10 | Variable cannot start with digit. | Python |
let a = 'output' | let a = "output" | Double quotes. | Swift |
$arr[100] | if ($arr.Count -gt 100) {{ $arr[100] }} | Check bounds. | PowerShell |
<hr></hr> | <hr> | Self-closing. | HTML |
{{"id":"message" "title":9}} | {{"id":"message", "title":9}} | Add comma. | JSON |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
void foo();
int main(){{foo();}} | void foo(); // prototype
int main(){{foo();}} | Declare before use. | C++ |
if (y) console.log('yes') else console.log('no') | if (y) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
console.log('info' | console.log('info') | Close parenthesis. | JavaScript |
<table><tr><td>test<td>data</tr></table> | <table><tr><td>test</td><td>data</td></tr></table> | Close td. | HTML |
if (bar = 32) {{}} | if (bar === 32) {{}} | Use === for equality. | JavaScript |
test | test() | Add parentheses. | Kotlin |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
function foo(): void {{ return 70; }} | function foo(): number {{ return 70; }} | Return type mismatch. | TypeScript |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
for (temp in list) | for (temp of list) | for...in iterates keys. | JavaScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(98); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('world')); app.listen(98, () => console.log('listening')); | Add callback. | Node.js |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
var item int = 'hello' | var item string = 'hello' | Type mismatch. | Go |
if b = 52 | if b == 52 | Use ==. | Go |
[98, 19, 51 | [98, 19, 51] | Close bracket. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
values[25] | if values.indices.contains(25) {{ values[25] }} | Check index. | Swift |
with open('input.csv') as f:
data = f.read() | with open('input.csv') as f:
data = f.read() | Correct. | Python |
let vec=vec![80,20,26]; let first=&vec[0]; vec.push(28); | let mut vec=vec![80,20,26]; let first=vec[0]; vec.push(28); | Copy instead of reference. | Rust |
print 'world' | print('world') | print needs parentheses. | Python |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
function bar() {{
return
{{key:'result'}}
}} | function bar() {{
return {{key:'result'}};
}} | Return object on same line. | JavaScript |
<person><desc>info</desc><name>52</name></person | <person><desc>info</desc><name>52</name></person> | Add closing >. | XML |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
if x = 60 then
print('test')
end | if x == 60 then
print('test')
end | Use ==. | Lua |
match a {{ 1 => {{}} }} | match a {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
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