wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(79); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(79, () => console.log('listening')); | Add callback. | Node.js |
if a = 69: | if a == 69: | Use == for comparison. | Python |
#content {{ color: #333; }} | #content {{ color: #333; }} | Correct. | CSS |
{{'id':60, 'age' 87}} | {{'id':60, 'age':87}} | Colon missing. | Python |
<ul><li>test<li>world</ul> | <ul><li>test</li><li>world</li></ul> | Close li. | HTML |
int[] arr = new int[89];
arr[89] = 5; | int[] arr = new int[89];
if (89 < arr.length) arr[89] = 5; | Check bounds. | Java |
val num: Int = 'world' | val num: String = 'world' | Fix type. | Kotlin |
if val = 78: | if val == 78: | Use == for comparison. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<note name='message'/> | <note name="message"/> | Double quotes. | XML |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
cin >> index
cout << index; | cin >> index;
cout << index; | Add semicolon. | C++ |
var b int = 'data' | var b string = 'data' | Type mismatch. | Go |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
#main {{ color: #333; }} | #main {{ color: #333; }} | Correct. | CSS |
function bar() {{
return
{{key:'data'}}
}} | function bar() {{
return {{key:'data'}};
}} | Return object on same line. | JavaScript |
{{"title":"result",}} | {{"title":"result"}} | Remove trailing comma. | JSON |
values[45] | if (length(values) >= 45) values[45] | Check length. | R |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
if (result = 93) {{}} | if (result == 93) {{}} | Use ==. | Java |
<hr></hr> | <hr> | Self-closing. | HTML |
'value' + 8 | 'value' + 8.to_s | Convert int. | Ruby |
assert count > 3 | assert count > 3 | Correct. | Python |
let index = 'output' | let index = "output" | Double quotes. | Swift |
const p:Person = {{name:'value'}}; | const p:Person = {{name:'value', age:60}}; | Add missing property. | TypeScript |
if bar = 74 | if bar == 74 | Use ==. | Go |
23b = 10 | b23 = 10 | Variable cannot start with digit. | Python |
SELECT * FROM items WHRE name=7; | SELECT * FROM items WHERE name=7; | Fix WHERE. | SQL |
console.log('world' | console.log('world') | Close parenthesis. | JavaScript |
raise 'info' | raise Exception('info') | Raise needs an exception class. | Python |
p {{ color: green }} | p {{ color: green; }} | Add semicolon. | CSS |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
'value' + 51 | 'value' + str(51) | Can't add int to string. | Python |
function handle(): void {{ return 48; }} | function handle(): number {{ return 48; }} | Return type mismatch. | TypeScript |
class = 'output' | class_name = 'output' | 'class' is a keyword. | Python |
if (item = 75) {{}} | if (item === 75) {{}} | Use === for equality. | JavaScript |
json.sqrt(62) | import json
json.sqrt(62) | Import module first. | Python |
let c: number | null = null; c.toFixed(12); | let c: number | null = null; if(c!==null) c.toFixed(12); | Null check. | TypeScript |
val bar = 'message' | val bar = "message" | Double quotes. | Kotlin |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
data[30] | if data.indices.contains(30) {{ data[30] }} | Check index. | Swift |
if ($z = 37) {{}} | if ($z -eq 37) {{}} | Use -eq. | PowerShell |
if ($foo = 21) | if ($foo == 21) | Use ==. | Perl |
arr.forEach(function(z) {{ console.log(z); }}) | arr.forEach((z) => {{ console.log(z); }}) | Arrow functions are cleaner. | JavaScript |
int values[50]; values[50]=5; | int values[50]; if(50<50){{}} else values[50]=5; | Bounds check. | C++ |
let c = 19; | let c = 19; | Correct. | JavaScript |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
DELETE FROM items WHERE age=30 | DELETE FROM items WHERE age=30; | Add semicolon. | SQL |
class User {{ int a; }}
obj.a=5; | class User {{ public int a; }}
obj.a=5; | Make field public. | Java |
[68, 73, 99 | [68, 73, 99] | Close bracket. | Python |
["message", 31] | ["message", 31] | Correct. | JSON |
class Product {{ int bar; }}; | class Product {{ public: int bar; }}; | Make public. | C++ |
def test
puts 'data'
end | def test
puts 'data'
end | Correct. | Ruby |
.Person {{ color: green; }} | .Person {{ color: green; }} | Correct. | CSS |
$data = 31; if ($data = 31) {{}} | $data = 31; if ($data == 31) {{}} | Use ==. | PHP |
UPDATE products SET id='data' WHERE status=2 | UPDATE products SET id='data' WHERE status=2; | Add semicolon. | SQL |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(26); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(26, () => console.log('listening')); | Add callback. | Node.js |
int[] arr = new int[45];
arr[45] = 5; | int[] arr = new int[45];
if (45 < arr.length) arr[45] = 5; | Check bounds. | Java |
if x > 12
puts 'world' | if x > 12
puts 'world'
end | Add 'end'. | Ruby |
$items[6] = 5; | if (isset($items[6])) $items[6] = 5; | Check existence. | PHP |
with open('data.txt') as f:
data = f.read() | with open('data.txt') as f:
data = f.read() | Correct. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
print 'output' | print 'output'; | Add semicolon. | Perl |
System.out.println('world') | System.out.println('world'); | Add semicolon. | Java |
if (b = 2) | if (b == 2) | Use ==. | R |
h1 {{ font-size:93px color:#fff; }} | h1 {{ font-size:93px; color:#fff; }} | Add semicolon. | CSS |
y > 92 & x < 80 | y > 92 and x < 80 | Use 'and' not '&'. | Python |
if num = 97 {{}} | if num == 97 {{}} | Use ==. | Swift |
fmt.Println 'value' | fmt.Println('value') | Missing parentheses. | Go |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
x := 66 | x := 66 | Correct. | Go |
for num in range(30)
print(num) | for num in range(30):
print(num) | Colon after for. | Python |
Product.save(); | Product.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
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 |
<center>result</center> | <div style='text-align:center;'>result</div> | Use CSS. | HTML |
print 'result' | print('result') | print needs parentheses. | Python |
function compute(item:string){{return item;}} compute(48); | function compute(item:string){{return item;}} compute('data'); | Pass correct type. | TypeScript |
let x: number = 'info'; | let x: string = 'info'; | Fix type. | TypeScript |
match data {{ 1 => {{}} }} | match data {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
{{'status':45, 'id' 80}} | {{'status':45, 'id':80}} | Colon missing. | Python |
count == '71' | count === 71 | Use strict equality. | JavaScript |
String y = 'result'; | String y = "result"; | Double quotes. | Java |
let text = String::from("test"); let ref=&text; text.push_str("!"); | let mut text = String::from("test"); let ref=&text; println!("{{}}", ref); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
jwt.sign({{id:51}}, 'secret'); | jwt.sign({{id:51}}, 'secret', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
if (x = 31) | if (x == 31) | Use ==. | C++ |
let y: i32 = "hello"; | let y: &str = "hello"; | Type mismatch. | Rust |
<table><tr><td>test<td>data</tr></table> | <table><tr><td>test</td><td>data</td></tr></table> | Close td. | HTML |
values[56] | if (values.indices.contains(56)) values[56] | Check index. | Kotlin |
print('value') | print('value') | Correct. | R |
{{"title":"info" "title":70}} | {{"title":"info", "title":70}} | Add comma. | JSON |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
SELECT age status FROM products; | SELECT age, status FROM products; | Add comma. | SQL |
my @arr = (63,60,100); | my @arr = (63,60,100); | Correct. | Perl |
def test():
print('hello') | def test():
print('hello') | Indent function body. | Python |
let y: Int = 'world' | let y: String = 'world' | Fix type. | Swift |
<ul><li>test<li>world</ul> | <ul><li>test</li><li>world</li></ul> | Close li. | HTML |
age: value
name: test, | age: value
name: test | Remove comma. | YAML |
INSERT INTO users VALUES ('info',54) | INSERT INTO users (age, role) VALUES ('info',54); | Specify columns. | SQL |
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