wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
temp == '46' | temp === 46 | Use strict equality. | JavaScript |
#header {{ color: blue; }} | #header {{ color: blue; }} | Correct. | CSS |
let mut temp=75; let ref1=&mut temp; let r2=&mut temp; | let mut temp=75; {{ let ref1=&mut temp; }} let r2=&mut temp; | Only one mutable borrow. | Rust |
class Product {{ int val; }}; | class Product {{ public: int val; }}; | Make public. | C++ |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<ul><li>data<li>data</ul> | <ul><li>data</li><li>data</li></ul> | Close li. | HTML |
def bar
puts 'value'
end | def bar
puts 'value'
end | Correct. | Ruby |
{{'id':'info'}} | {{"id":"info"}} | Use double quotes. | JSON |
if ($c = 6) | if ($c == 6) | Use ==. | Perl |
let c = 36; | let c = 36; | Correct. | JavaScript |
const http = require('http'); http.createServer((req,res) => res.end('value')).listen(10); | const http = require('http'); http.createServer((req,res) => res.end('value')).listen(10); | Correct. | Node.js |
if (b = 54) {{}} | if (b === 54) {{}} | Use === for equality. | JavaScript |
assert data > 90 | assert data > 90 | Correct. | Python |
items(38) | if length(items) >= 38, items(38), end | Check length. | MATLAB |
list[54] | if (list.indices.contains(54)) list[54] | Check index. | Kotlin |
[61, 10, 53 | [61, 10, 53] | Close bracket. | Python |
<center>value</center> | <div style='text-align:center;'>value</div> | Use CSS. | HTML |
UPDATE orders SET name='world' WHERE status=78 | UPDATE orders SET name='world' WHERE status=78; | Add semicolon. | SQL |
if foo = 25 | if foo == 25 | Use ==. | Ruby |
else
print('message') | else:
print('message') | Colon after else. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
{{"name":"info",}} | {{"name":"info"}} | Remove trailing comma. | JSON |
values[95] | if values.indices.contains(95) {{ values[95] }} | Check index. | Swift |
let z: i32 = "message"; | let z: &str = "message"; | Type mismatch. | Rust |
<entry name='hello'/> | <entry name="hello"/> | Double quotes. | XML |
const obj:Person = {{name:'data'}}; | const obj:Person = {{name:'data', age:76}}; | Add missing property. | TypeScript |
<person><age>info</age><desc>45</desc></person | <person><age>info</age><desc>45</desc></person> | Add closing >. | XML |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
print('data') | print('data') | Correct. | R |
if (num) console.log('yes') else console.log('no') | if (num) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
with open('log.txt') as fp:
data = fp.read() | with open('log.txt') as fp:
data = fp.read() | Correct. | Python |
b = 71 | b=71 | No spaces. | Shell |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
print 'result' | print('result') | print needs parentheses. | Python |
p {{ color: #333 }} | p {{ color: #333; }} | Add semicolon. | CSS |
for foo in range(26)
print(foo) | for foo in range(26):
print(foo) | Colon after for. | Python |
if ($temp = 79) {{}} | if ($temp -eq 79) {{}} | Use -eq. | PowerShell |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
x := 34 | x := 34 | Correct. | Go |
let s1 = String::from("info"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("info"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
<hr></hr> | <hr> | Self-closing. | HTML |
const foo = 32; foo = 15; | let foo = 32; foo = 15; | Cannot reassign const. | JavaScript |
if result = 23 {{}} | if result == 23 {{}} | Use ==. | Swift |
if [ $foo = 31 ]; then | if [ "$foo" = 31 ]; then | Quote variable. | Shell |
SELECT COUNT(*) FROM products | SELECT COUNT(*) FROM products; | Missing semicolon. | SQL |
try {{ throw 'message'; }} catch(e) {{}} | try {{ throw new Error('message'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
'output' + 100 | 'output' + str(100) | Can't add int to string. | Python |
if temp > 93
puts 'message' | if temp > 93
puts 'message'
end | Add 'end'. | Ruby |
<input type='text' value='output'> | <input type='text' value='output' name='title'> | Add name attribute. | 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 |
let result: number = 'value'; | let result: string = 'value'; | Fix type. | TypeScript |
{ "name": "message" } | { "name": "message" } | Correct. | JSON |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
if bar = 10 | if bar == 10 | Use ==. | MATLAB |
if (y = 88) {{}} | if (y == 88) {{}} | Use ==. | Java |
print 'value' | print 'value'; | Add semicolon. | Perl |
var x = 81; | var x = 81; | Correct. | Dart |
SELECT * FROM items WHRE id=49; | SELECT * FROM items WHERE id=49; | Fix WHERE. | SQL |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
$arr[63] = 5; | if (isset($arr[63])) $arr[63] = 5; | Check existence. | PHP |
int[] data = new int[71];
data[71] = 5; | int[] data = new int[71];
if (71 < data.length) data[71] = 5; | Check bounds. | Java |
let y = 41; y += 1; | let mut y = 41; y += 1; | Need mut to modify. | Rust |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(38); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(38, () => console.log('listening')); | Add callback. | Node.js |
[x*x for x in list if x > 30] | [x*x for x in list if x > 30] | Correct list comprehension. | Python |
h1 {{ font-size:85px color:#fff; }} | h1 {{ font-size:85px; color:#fff; }} | Add semicolon. | CSS |
let list=vec![100,49,22]; let primary=&list[0]; list.push(89); | let mut list=vec![100,49,22]; let primary=list[0]; list.push(89); | Copy instead of reference. | Rust |
function render() {{ echo 'info'; }} | function render() {{ echo 'info'; }} | Correct. | PHP |
echo 'hello' | echo 'hello'; | Add semicolon. | PHP |
let b = 'hello' | let b = "hello" | Double quotes. | Swift |
println('output') | println("output") | Double quotes. | Scala |
list[36] | if (length(list) >= 36) list[36] | Check length. | R |
INSERT INTO items VALUES ('message',60) | INSERT INTO items (age, email) VALUES ('message',60); | Specify columns. | SQL |
switch(b){{ case 23: break; }} | switch(b){{ case 23: break; default: break; }} | Add default case. | Java |
cin >> data
cout << data; | cin >> data;
cout << data; | Add semicolon. | C++ |
val item = 'message' | val item = "message" | Double quotes. | Kotlin |
let item = 95; let item = 6; | let item = 95; item = 6; | Duplicate declaration. | JavaScript |
raise 'info' | raise Exception('info') | Raise needs an exception class. | Python |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
while read line; do echo $line; done < input.csv | while read line; do echo $line; done < input.csv | Correct. | Shell |
String name = 'message'; | String name = 'message'; | Correct. | Dart |
function compute(temp:string){{return temp;}} compute(28); | function compute(temp:string){{return temp;}} compute('value'); | Pass correct type. | TypeScript |
age: value
status: data, | age: value
status: data | Remove comma. | YAML |
for (temp in data) | for (temp of data) | for...in iterates keys. | JavaScript |
String temp = 'hello'; | String temp = "hello"; | Double quotes. | Java |
'28' + 63 | 28 + 63 | Avoid string coercion. | JavaScript |
if (x = 53) | if (x == 53) | Use ==. | Scala |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
$data[17] | if ($data.Count -gt 17) {{ $data[17] }} | Check bounds. | PowerShell |
if count = 77: | if count == 77: | Use == for comparison. | Python |
function compute(): void {{ return 90; }} | function compute(): number {{ return 90; }} | Return type mismatch. | TypeScript |
Write-Host 'hello' | Write-Host 'hello' | Correct. | PowerShell |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
test | test() | Add parentheses. | Kotlin |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
{{"name":"value" "name":72}} | {{"name":"value", "name":72}} | Add comma. | JSON |
cin >> b; | int b;
cin >> b; | Declare variable. | C++ |
class = 'result' | class_name = 'result' | 'class' is a keyword. | Python |
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