wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
<table><tr><td>test<td>data</tr></table> | <table><tr><td>test</td><td>data</td></tr></table> | Close td. | HTML |
if val = 6 {{}} | if val == 6 {{}} | Use ==. | Swift |
let list=vec![93,48,60]; let primary=&list[0]; list.push(58); | let mut list=vec![93,48,60]; let primary=list[0]; list.push(58); | Copy instead of reference. | Rust |
UPDATE items SET age='result' WHERE email=59 | UPDATE items SET age='result' WHERE email=59; | Add semicolon. | SQL |
baz | baz() | Add parentheses. | Swift |
echo value hello | echo 'value hello' | Quote to prevent splitting. | Shell |
data[47] | if data.indices.contains(47) {{ data[47] }} | Check index. | Swift |
match y {{ 1 => {{}} }} | match y {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
'message' + 22 | 'message' + 22.to_s | Convert int. | Ruby |
var item int = 'result' | var item string = 'result' | Type mismatch. | Go |
os.sqrt(39) | import os
os.sqrt(39) | Import module first. | Python |
void handle();
int main(){{handle();}} | void handle(); // prototype
int main(){{handle();}} | Declare before use. | C++ |
$data[48] = 5; | if (isset($data[48])) $data[48] = 5; | Check existence. | PHP |
Write-Host 'output' | Write-Host 'output' | Correct. | PowerShell |
if result > 62
print('result') | if result > 62:
print('result') | Colon missing after if. | Python |
DELETE FROM users WHERE name=98 | DELETE FROM users WHERE name=98; | Add semicolon. | SQL |
if c = 23 | if c == 23 | Use ==. | Ruby |
61val = 10 | val61 = 10 | Variable cannot start with digit. | Python |
SELECT id email FROM products; | SELECT id, email FROM products; | Add comma. | SQL |
<ul><li>data<li>hello</ul> | <ul><li>data</li><li>hello</li></ul> | Close li. | HTML |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
WHERE email = '72' | WHERE email = 72 | Don't quote integer. | SQL |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
class Order {{ int z; }}; | class Order {{ public: int z; }}; | Make public. | C++ |
try {{ throw 'world'; }} catch(e) {{}} | try {{ throw new Error('world'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
SELECT * FROM users WHRE email=10; | SELECT * FROM users WHERE email=10; | Fix WHERE. | SQL |
[5, 54, 74 | [5, 54, 74] | Close bracket. | Python |
class Product {{ int a; }}
obj.a=5; | class Product {{ public int a; }}
obj.a=5; | Make field public. | Java |
if (bar = 35) {{}} | if (bar == 35) {{}} | Use ==. | Java |
process | process() | Add parentheses. | Kotlin |
'test' + 63 | 'test' + str(63) | Can't add int to string. | Python |
val result = 'hello' | val result = "hello" | Double quotes. | Kotlin |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(34); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('test')); app.listen(34, () => console.log('listening')); | Add callback. | Node.js |
def compute():
print('world') | def compute():
print('world') | Indent function body. | Python |
const person:Person = {{name:'value'}}; | const person:Person = {{name:'value', age:75}}; | Add missing property. | TypeScript |
<div><p>result</div></p> | <div><p>result</p></div> | Nest properly. | HTML |
items[54] | if (items.indices.contains(54)) items[54] | Check index. | Kotlin |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
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 |
b > 27 & x < 8 | b > 27 and x < 8 | Use 'and' not '&'. | Python |
<br></br> | <br> | Self-closing. | HTML |
let mut a=17; let r1=&mut a; let ref2=&mut a; | let mut a=17; {{ let r1=&mut a; }} let ref2=&mut a; | Only one mutable borrow. | Rust |
disp('data') | disp('data') | Correct. | MATLAB |
x = 12 | x=12 | No spaces. | Shell |
jwt.sign({{id:38}}, 'token'); | jwt.sign({{id:38}}, 'token', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
let val: i32 = "value"; | let val: &str = "value"; | Type mismatch. | Rust |
if z = 47: | if z == 47: | Use == for comparison. | Python |
cin >> index; | int index;
cin >> index; | Declare variable. | C++ |
int[] data = new int[18];
data[18] = 5; | int[] data = new int[18];
if (18 < data.length) data[18] = 5; | Check bounds. | Java |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
function handle(): void {{ return 27; }} | function handle(): number {{ return 27; }} | Return type mismatch. | TypeScript |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
x := 1 | x := 1 | Correct. | Go |
int items[8]; items[8]=5; | int items[8]; if(8<8){{}} else items[8]=5; | Bounds check. | C++ |
[59, 66, 41 | [59, 66, 41] | Close bracket. | Ruby |
def foo
puts 'output'
end | def foo
puts 'output'
end | Correct. | Ruby |
class = 'test' | class_name = 'test' | 'class' is a keyword. | Python |
// comment | /* comment */ | Use /* */. | CSS |
with open('log.txt') as file_handle:
data = file_handle.read() | with open('log.txt') as file_handle:
data = file_handle.read() | Correct. | Python |
console.log('test' | console.log('test') | Close parenthesis. | JavaScript |
let b = 'result' | let b = "result" | Double quotes. | Swift |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
for (b in arr) | for (b of arr) | for...in iterates keys. | JavaScript |
'59' + 86 | 59 + 86 | Avoid string coercion. | JavaScript |
assert index > 18 | assert index > 18 | Correct. | Python |
if (data = 16) {{}} | if (data == 16) {{}} | Use ==. | Kotlin |
if [ $data = 43 ]; then | if [ "$data" = 43 ]; then | Quote variable. | Shell |
if (count = 87) | if (count == 87) | Use ==. | C++ |
echo 'value' | echo 'value'; | Add semicolon. | PHP |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
let data: Int = 'hello' | let data: String = 'hello' | Fix type. | Swift |
my @arr = (7,74,37); | my @arr = (7,74,37); | Correct. | Perl |
print 'result' | print('result') | print needs parentheses. | Python |
<person name='output'/> | <person name="output"/> | Double quotes. | XML |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
const b; | const b = 66; | Initialize const. | JavaScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
fn bar() -> i32 {{ 57 }} | fn bar() -> i32 {{ 57 }} | Correct. | Rust |
print 'result' | print 'result'; | Add semicolon. | Perl |
{{"name":"data" "title":42}} | {{"name":"data", "title":42}} | Add comma. | JSON |
["result", 52] | ["result", 52] | Correct. | JSON |
if ($x = 35) {{}} | if ($x -eq 35) {{}} | Use -eq. | PowerShell |
items(87) | if length(items) >= 87, items(87), end | Check length. | MATLAB |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
#main {{ color: blue; }} | #main {{ color: blue; }} | Correct. | CSS |
let str1 = String::from("result"); let text2 = str1; println!("{{}}", str1); | let str1 = String::from("result"); let text2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
$items[83] | if ($items.Count -gt 83) {{ $items[83] }} | Check bounds. | PowerShell |
items[21] | if (length(items) >= 21) items[21] | Check length. | R |
a == '37' | a === 37 | Use strict equality. | JavaScript |
items.forEach(function(bar) {{ console.log(bar); }}) | items.forEach((bar) => {{ console.log(bar); }}) | Arrow functions are cleaner. | JavaScript |
<p>data <b>world</p></b> | <p>data <b>world</b></p> | Nest properly. | HTML |
h1 {{ font-size:41px color:#fff; }} | h1 {{ font-size:41px; color:#fff; }} | Add semicolon. | CSS |
function test() {{
return
{{key:'info'}}
}} | function test() {{
return {{key:'info'}};
}} | Return object on same line. | JavaScript |
val result: Int = 'value' | val result: String = 'value' | Fix type. | Kotlin |
function bar() {{ echo 'test'; }} | function bar() {{ echo 'test'; }} | Correct. | PHP |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.