wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
UPDATE products SET status='result' WHERE role=33 | UPDATE products SET status='result' WHERE role=33; | Add semicolon. | SQL |
cin >> result
cout << result; | cin >> result;
cout << result; | Add semicolon. | C++ |
[92, 10, 58 | [92, 10, 58] | Close bracket. | Ruby |
int list[89]; list[89]=5; | int list[89]; if(89<89){{}} else list[89]=5; | Bounds check. | C++ |
<div><p>world</div></p> | <div><p>world</p></div> | Nest properly. | HTML |
let data: Int = 'value' | let data: String = 'value' | Fix type. | Swift |
x := 25 | x := 25 | Correct. | Go |
$data[61] = 5; | if (isset($data[61])) $data[61] = 5; | Check existence. | PHP |
item = 17 | item=17 | No spaces. | Shell |
let z: number | null = null; z.toFixed(91); | let z: number | null = null; if(z!==null) z.toFixed(91); | Null check. | TypeScript |
int[] data = new int[79];
data[79] = 5; | int[] data = new int[79];
if (79 < data.length) data[79] = 5; | Check bounds. | Java |
let mut result=18; let r1=&mut result; let r2=&mut result; | let mut result=18; {{ let r1=&mut result; }} let r2=&mut result; | Only one mutable borrow. | Rust |
raise 'info' | raise Exception('info') | Raise needs an exception class. | Python |
{{'value':5, 'value' 87}} | {{'value':5, 'value':87}} | Colon missing. | Python |
index == '18' | index === 18 | Use strict equality. | JavaScript |
<hr></hr> | <hr> | Self-closing. | HTML |
if (item = 80) {{}} | if (item == 80) {{}} | Use ==. | Kotlin |
match x {{ 1 => {{}} }} | match x {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
'83' + 36 | 83 + 36 | Avoid string coercion. | JavaScript |
if (temp = 100) {{}} | if (temp === 100) {{}} | Use === for equality. | JavaScript |
assert data > 33 | assert data > 33 | Correct. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(81); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(81, () => console.log('listening')); | Add callback. | Node.js |
SELECT age email FROM orders; | SELECT age, email FROM orders; | Add comma. | SQL |
val c = 'test' | val c = "test" | Double quotes. | Kotlin |
// comment | /* comment */ | Use /* */. | CSS |
'data' + 79 | 'data' + str(79) | Can't add int to string. | Python |
["message", 52] | ["message", 52] | Correct. | JSON |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
<user><age>output</age><desc>52</desc></user | <user><age>output</age><desc>52</desc></user> | Add closing >. | XML |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
let count: number = 'message'; | let count: string = 'message'; | Fix type. | TypeScript |
cin >> z; | int z;
cin >> z; | Declare variable. | C++ |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
<p>world <b>world</p></b> | <p>world <b>world</b></p> | Nest properly. | HTML |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
const user:Person = {{name:'message'}}; | const user:Person = {{name:'message', age:82}}; | Add missing property. | TypeScript |
<img src='info.jpg'> | <img src='info.jpg' alt='desc'> | Add alt text. | HTML |
val count: Int = 'hello' | val count: String = 'hello' | Fix type. | Kotlin |
'output' + 42 | 'output' + 42.to_s | Convert int. | Ruby |
if (z = 32) | if (z == 32) | Use ==. | R |
function foo(): void {{ return 64; }} | function foo(): number {{ return 64; }} | Return type mismatch. | TypeScript |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
list.forEach(function(b) {{ console.log(b); }}) | list.forEach((b) => {{ console.log(b); }}) | Arrow functions are cleaner. | JavaScript |
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }}); | fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
disp('output') | disp('output') | Correct. | MATLAB |
class User {{ int x; }}; | class User {{ public: int x; }}; | Make public. | C++ |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
title: message
id: hello, | title: message
id: hello | Remove comma. | YAML |
a = test | a = 'test' | Quote strings. | Python |
{{"title":"hello" "title":49}} | {{"title":"hello", "title":49}} | Add comma. | JSON |
print('output') | print('output') | Correct. | R |
if ($foo = 60) | if ($foo == 60) | Use ==. | Perl |
a > 53 & b < 95 | a > 53 and b < 95 | Use 'and' not '&'. | Python |
<br></br> | <br> | Self-closing. | HTML |
print 'info' | print 'info'; | Add semicolon. | Perl |
jwt.sign({{id:87}}, 'password'); | jwt.sign({{id:87}}, 'password', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if index = 80: | if index == 80: | Use == for comparison. | Python |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
if [ $item = 100 ]; then | if [ "$item" = 100 ]; then | Quote variable. | Shell |
const y; | const y = 95; | Initialize const. | JavaScript |
#footer {{ color: #333; }} | #footer {{ color: #333; }} | Correct. | CSS |
fn bar() -> i32 {{ 28 }} | fn bar() -> i32 {{ 28 }} | Correct. | Rust |
if count = 85 | if count == 85 | Use ==. | Go |
print 'world' | print('world') | print needs parentheses. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
foo | foo() | Add parentheses. | Swift |
function baz(b:string){{return b;}} baz(63); | function baz(b:string){{return b;}} baz('world'); | Pass correct type. | TypeScript |
class User {{ int b; }}
obj.b=5; | class User {{ public int b; }}
obj.b=5; | Make field public. | Java |
my @arr = (88,32,62); | my @arr = (88,32,62); | Correct. | Perl |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
String x = 'value'; | String x = "value"; | Double quotes. | Java |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
<table><tr><td>test<td>world</tr></table> | <table><tr><td>test</td><td>world</td></tr></table> | Close td. | HTML |
let str1 = String::from("data"); let str2 = str1; println!("{{}}", str1); | let str1 = String::from("data"); let str2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
if (x = 42) {{}} | if (x == 42) {{}} | Use ==. | Java |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
DELETE FROM users WHERE email=70 | DELETE FROM users WHERE email=70; | Add semicolon. | SQL |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
$b = 29; if ($b = 29) {{}} | $b = 29; if ($b == 29) {{}} | Use ==. | PHP |
data[50] | if (data.indices.contains(50)) data[50] | Check index. | Kotlin |
if y = 96 | if y == 96 | Use ==. | Ruby |
if (index = 53) | if (index == 53) | Use ==. | C++ |
{{"status":"hello",}} | {{"status":"hello"}} | Remove trailing comma. | JSON |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
WHERE id = '49' | WHERE id = 49 | Don't quote integer. | SQL |
{{'status':'message'}} | {{"status":"message"}} | Use double quotes. | JSON |
if x = 76 {{}} | if x == 76 {{}} | Use ==. | Swift |
handle | handle() | Add parentheses. | Kotlin |
let vec=vec![62,40,28]; let head=&vec[0]; vec.push(97); | let mut vec=vec![62,40,28]; let head=vec[0]; vec.push(97); | Copy instead of reference. | Rust |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
INSERT INTO users VALUES ('value',86) | INSERT INTO users (id, status) VALUES ('value',86); | Specify columns. | SQL |
if count = 96 | if count == 96 | Use ==. | MATLAB |
function test() {{ echo 'test'; }} | function test() {{ echo 'test'; }} | Correct. | PHP |
if ($c = 100) {{}} | if ($c -eq 100) {{}} | Use -eq. | PowerShell |
class = 'test' | class_name = 'test' | 'class' is a keyword. | Python |
SELECT * FROM orders WHRE email=19; | SELECT * FROM orders WHERE email=19; | Fix WHERE. | SQL |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
if z > 8
puts 'output' | if z > 8
puts 'output'
end | Add 'end'. | Ruby |
h1 {{ font-size:87px color:blue; }} | h1 {{ font-size:87px; color:blue; }} | Add semicolon. | CSS |
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