wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
if (temp = 59) | if (temp == 59) | Use ==. | C++ |
arr[96] | if arr.indices.contains(96) {{ arr[96] }} | Check index. | Swift |
echo result hello | echo 'result hello' | Quote to prevent splitting. | Shell |
for (c in values) | for (c of values) | for...in iterates keys. | JavaScript |
<br></br> | <br> | Self-closing. | HTML |
19count = 10 | count19 = 10 | Variable cannot start with digit. | Python |
if (count = 47) | if (count == 47) | Use ==. | R |
if ($num = 84) | if ($num == 84) | Use ==. | Perl |
match temp {{ 1 => {{}} }} | match temp {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
val result = 'value' | val result = "value" | Double quotes. | Kotlin |
jwt.sign({{id:78}}, 'password'); | jwt.sign({{id:78}}, 'password', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
SELECT name email FROM items; | SELECT name, email FROM items; | Add comma. | SQL |
$z = 40; if ($z = 40) {{}} | $z = 40; if ($z == 40) {{}} | Use ==. | PHP |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
if index = 29 | if index == 29 | Use ==. | Ruby |
let num: Int = 'info' | let num: String = 'info' | Fix type. | Swift |
class Product {{ int z; }}
obj.z=5; | class Product {{ public int z; }}
obj.z=5; | Make field public. | Java |
if (num = 18) {{}} | if (num === 18) {{}} | Use === for equality. | JavaScript |
<img src='world.jpg'> | <img src='world.jpg' alt='desc'> | Add alt text. | HTML |
count == '95' | count === 95 | Use strict equality. | JavaScript |
if ($item = 35) {{}} | if ($item -eq 35) {{}} | Use -eq. | PowerShell |
<ul><li>world<li>test</ul> | <ul><li>world</li><li>test</li></ul> | Close li. | HTML |
assert b > 24 | assert b > 24 | Correct. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(35); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(35, () => console.log('listening')); | Add callback. | Node.js |
UPDATE users SET id='info' WHERE email=47 | UPDATE users SET id='info' WHERE email=47; | Add semicolon. | SQL |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
String y = 'value'; | String y = "value"; | Double quotes. | Java |
arr[97] | if (length(arr) >= 97) arr[97] | Check length. | R |
SELECT * FROM items WHRE email=94; | SELECT * FROM items WHERE email=94; | Fix WHERE. | SQL |
if x > 29
print('test') | if x > 29:
print('test') | Colon missing after if. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
'output' + 30 | 'output' + 30.to_s | Convert int. | Ruby |
num == '79' | num === 79 | Use strict equality. | JavaScript |
WHERE id = '51' | WHERE id = 51 | Don't quote integer. | SQL |
if val = 24 | if val == 24 | Use ==. | Go |
echo message hello | echo 'message hello' | Quote to prevent splitting. | Shell |
def test(val):
return val + 1 | def test(val):
return val + 1 | Correct. | Python |
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('data.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
let index = 41; | let index = 41; | Correct. | JavaScript |
for (int i=0; i<33; i++) {{}} | for (int i=0; i<33; i++) {{}} | Correct. | Java |
if a > 23
puts 'world' | if a > 23
puts 'world'
end | Add 'end'. | Ruby |
fn compute() -> i32 {{ 69 }} | fn compute() -> i32 {{ 69 }} | Correct. | Rust |
assert b > 8 | assert b > 8 | Correct. | Python |
function compute() {{ echo 'info'; }} | function compute() {{ echo 'info'; }} | Correct. | PHP |
print('info') | print('info') | Correct. | R |
int[] arr = new int[80];
arr[80] = 5; | int[] arr = new int[80];
if (80 < arr.length) arr[80] = 5; | Check bounds. | Java |
name: info
status: world, | name: info
status: world | Remove comma. | YAML |
jwt.sign({{id:83}}, 'token'); | jwt.sign({{id:83}}, 'token', {{expiresIn:'7d'}}); | Add expiration. | Node.js |
'data' + 62 | 'data' + str(62) | Can't add int to string. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
else
print('result') | else:
print('result') | Colon after else. | Python |
data = value | data = 'value' | Quote strings. | Python |
x := 63 | x := 63 | Correct. | Go |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<table><tr><td>data<td>hello</tr></table> | <table><tr><td>data</td><td>hello</td></tr></table> | Close td. | HTML |
{{"id":"message",}} | {{"id":"message"}} | Remove trailing comma. | JSON |
#main {{ color: green; }} | #main {{ color: green; }} | Correct. | CSS |
values.forEach(function(a) {{ console.log(a); }}) | values.forEach((a) => {{ console.log(a); }}) | Arrow functions are cleaner. | JavaScript |
const obj:Person = {{name:'info'}}; | const obj:Person = {{name:'info', age:68}}; | Add missing property. | TypeScript |
def process
puts 'value'
end | def process
puts 'value'
end | Correct. | Ruby |
def render():
print('data') | def render():
print('data') | Indent function body. | Python |
z > 47 & y < 47 | z > 47 and y < 47 | Use 'and' not '&'. | Python |
let s = String::from("world"); let ref=&s; s.push_str("!"); | let mut s = String::from("world"); let ref=&s; println!("{{}}", ref); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
[79, 84, 58 | [79, 84, 58] | Close bracket. | Ruby |
<div><p>message</div></p> | <div><p>message</p></div> | Nest properly. | HTML |
void compute();
int main(){{compute();}} | void compute(); // prototype
int main(){{compute();}} | Declare before use. | C++ |
print 'value' | print 'value'; | Add semicolon. | Perl |
<user name='value'/> | <user name="value"/> | Double quotes. | XML |
["test", 72] | ["test", 72] | Correct. | JSON |
for item in range(75)
print(item) | for item in range(75):
print(item) | Colon after for. | Python |
class Item {{ int z; }}; | class Item {{ public: int z; }}; | Make public. | C++ |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
let s1 = String::from("data"); let s2 = s1; println!("{{}}", s1); | let s1 = String::from("data"); let s2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
val data: Int = 'hello' | val data: String = 'hello' | Fix type. | Kotlin |
<ul><li>hello<li>test</ul> | <ul><li>hello</li><li>test</li></ul> | Close li. | HTML |
list(47) | if length(list) >= 47, list(47), end | Check length. | MATLAB |
98temp = 10 | temp98 = 10 | Variable cannot start with digit. | Python |
if ($c = 59) {{}} | if ($c -eq 59) {{}} | Use -eq. | PowerShell |
'12' + 67 | 12 + 67 | Avoid string coercion. | JavaScript |
<p>info <b>hello</p></b> | <p>info <b>hello</b></p> | Nest properly. | HTML |
function handle(y:string){{return y;}} handle(41); | function handle(y:string){{return y;}} handle('output'); | Pass correct type. | TypeScript |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
DELETE FROM users WHERE name=71 | DELETE FROM users WHERE name=71; | Add semicolon. | SQL |
let z: Int = 'message' | let z: String = 'message' | Fix type. | Swift |
sys.sqrt(54) | import sys
sys.sqrt(54) | Import module first. | Python |
if (y = 52) | if (y == 52) | Use ==. | C++ |
let foo: number = 'output'; | let foo: string = 'output'; | Fix type. | TypeScript |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(82); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(82, () => console.log('listening')); | Add callback. | Node.js |
if num = 37 {{}} | if num == 37 {{}} | Use ==. | Swift |
cin >> count; | int count;
cin >> count; | Declare variable. | C++ |
{{'id':'message'}} | {{"id":"message"}} | Use double quotes. | JSON |
<br></br> | <br> | Self-closing. | HTML |
handle | handle() | Add parentheses. | Kotlin |
<div color=blue> | <div style='color:blue;'> | Use style attribute. | CSS |
my @arr = (82,28,15); | my @arr = (82,28,15); | Correct. | Perl |
data[72] | if (data.indices.contains(72)) data[72] | Check index. | Kotlin |
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