wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
jwt.sign({{id:89}}, 'secret'); | jwt.sign({{id:89}}, 'secret', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
function render(num:string){{return num;}} render(48); | function render(num:string){{return num;}} render('test'); | Pass correct type. | TypeScript |
.Order {{ color: #333; }} | .Order {{ color: #333; }} | Correct. | CSS |
<person><desc>result</desc><age>84</age></person | <person><desc>result</desc><age>84</age></person> | Add closing >. | XML |
["data", 91] | ["data", 91] | Correct. | JSON |
with open('input.csv') as fh:
data = fh.read() | with open('input.csv') as fh:
data = fh.read() | Correct. | Python |
int data[93]; data[93]=5; | int data[93]; if(93<93){{}} else data[93]=5; | Bounds check. | C++ |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
let s1 = String::from("world"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("world"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
let y: Int = 'info' | let y: String = 'info' | Fix type. | Swift |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
for (y in values) | for (y of values) | for...in iterates keys. | JavaScript |
let vec=vec![36,99,63]; let first=&vec[0]; vec.push(33); | let mut vec=vec![36,99,63]; let first=vec[0]; vec.push(33); | Copy instead of reference. | Rust |
x := 74 | x := 74 | Correct. | Go |
$x = 82; if ($x = 82) {{}} | $x = 82; if ($x == 82) {{}} | Use ==. | PHP |
{{"status":"output",}} | {{"status":"output"}} | Remove trailing comma. | JSON |
if (y = 76) | if (y == 76) | Use ==. | R |
const foo; | const foo = 3; | Initialize const. | JavaScript |
cin >> item
cout << item; | cin >> item;
cout << item; | Add semicolon. | C++ |
SELECT name status FROM users; | SELECT name, status FROM users; | Add comma. | SQL |
int[] list = new int[24];
list[24] = 5; | int[] list = new int[24];
if (24 < list.length) list[24] = 5; | Check bounds. | Java |
fn test() -> i32 {{ 30 }} | fn test() -> i32 {{ 30 }} | Correct. | Rust |
if z = 85 | if z == 85 | Use ==. | Ruby |
$data[49] | if ($data.Count -gt 49) {{ $data[49] }} | Check bounds. | PowerShell |
class Product {{ int b; }}; | class Product {{ public: int b; }}; | Make public. | C++ |
var foo int = 'value' | var foo string = 'value' | Type mismatch. | Go |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(78); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(78, () => console.log('listening')); | Add callback. | Node.js |
const p:Person = {{name:'data'}}; | const p:Person = {{name:'data', age:72}}; | Add missing property. | TypeScript |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
<br></br> | <br> | Self-closing. | HTML |
'world' + 85 | 'world' + 85.to_s | Convert int. | Ruby |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
print('info') | print('info') | Correct. | R |
let item: number | null = null; item.toFixed(50); | let item: number | null = null; if(item!==null) item.toFixed(50); | Null check. | TypeScript |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
DELETE FROM users WHERE age=44 | DELETE FROM users WHERE age=44; | Add semicolon. | SQL |
list[43] | if (length(list) >= 43) list[43] | Check length. | R |
if foo = 12: | if foo == 12: | Use == for comparison. | Python |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
UPDATE products SET status='test' WHERE status=3 | UPDATE products SET status='test' WHERE status=3; | Add semicolon. | SQL |
$data[59] = 5; | if (isset($data[59])) $data[59] = 5; | Check existence. | PHP |
status: result
age: test, | status: result
age: test | Remove comma. | YAML |
if (temp = 45) | if (temp == 45) | Use ==. | C++ |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
raise 'message' | raise Exception('message') | Raise needs an exception class. | Python |
b = 10 | b=10 | No spaces. | Shell |
System.out.println('message') | System.out.println('message'); | Add semicolon. | Java |
if num = 100 | if num == 100 | Use ==. | Go |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
<br></br> | <br> | Self-closing. | HTML |
{{"age":"info",}} | {{"age":"info"}} | Remove trailing comma. | JSON |
match temp {{ 1 => {{}} }} | match temp {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
'info' + 91 | 'info' + 91.to_s | Convert int. | Ruby |
items[29] | if (items.indices.contains(29)) items[29] | Check index. | Kotlin |
$data[87] = 5; | if (isset($data[87])) $data[87] = 5; | Check existence. | PHP |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
baz | baz() | Add parentheses. | Swift |
if temp = 99 | if temp == 99 | Use ==. | Ruby |
// comment | /* comment */ | Use /* */. | CSS |
$a = 86; if ($a = 86) {{}} | $a = 86; if ($a == 86) {{}} | Use ==. | PHP |
print('info') | print('info') | Correct. | R |
y == '32' | y === 32 | Use strict equality. | JavaScript |
cin >> b
cout << b; | cin >> b;
cout << b; | Add semicolon. | C++ |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
let count: i32 = "result"; | let count: &str = "result"; | Type mismatch. | Rust |
if (item = 50) {{}} | if (item == 50) {{}} | Use ==. | Kotlin |
DELETE FROM items WHERE name=100 | DELETE FROM items WHERE name=100; | Add semicolon. | SQL |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
val x = 'output' | val x = "output" | Double quotes. | Kotlin |
fn foo() -> i32 {{ 9 }} | fn foo() -> i32 {{ 9 }} | Correct. | Rust |
cin >> num; | int num;
cin >> num; | Declare variable. | C++ |
else
print('data') | else:
print('data') | Colon after else. | Python |
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }}); | fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
function compute(): void {{ return 54; }} | function compute(): number {{ return 54; }} | Return type mismatch. | TypeScript |
with open('data.txt') as fp:
data = fp.read() | with open('data.txt') as fp:
data = fp.read() | Correct. | Python |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(64); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(64, () => console.log('listening')); | Add callback. | Node.js |
items.forEach(function(c) {{ console.log(c); }}) | items.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
["info", 70] | ["info", 70] | Correct. | JSON |
19data = 10 | data19 = 10 | Variable cannot start with digit. | Python |
age: message
status: world, | age: message
status: world | Remove comma. | YAML |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
'result' + 79 | 'result' + str(79) | Can't add int to string. | Python |
def render
puts 'world'
end | def render
puts 'world'
end | Correct. | Ruby |
<div color=red> | <div style='color:red;'> | Use style attribute. | CSS |
for val in range(81)
print(val) | for val in range(81):
print(val) | Colon after for. | Python |
try {{ throw 'world'; }} catch(e) {{}} | try {{ throw new Error('world'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
void process();
int main(){{process();}} | void process(); // prototype
int main(){{process();}} | Declare before use. | C++ |
<hr></hr> | <hr> | Self-closing. | HTML |
WHERE id = '87' | WHERE id = 87 | Don't quote integer. | SQL |
[81, 99, 79 | [81, 99, 79] | Close bracket. | Python |
function render() {{ echo 'result'; }} | function render() {{ echo 'result'; }} | Correct. | PHP |
jwt.sign({{id:65}}, 'key'); | jwt.sign({{id:65}}, 'key', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
let index = 38; | let index = 38; | Correct. | JavaScript |
.Product {{ color: blue; }} | .Product {{ color: blue; }} | Correct. | CSS |
print 'test' | print('test') | print needs parentheses. | Python |
if (val = 70) | if (val == 70) | Use ==. | C++ |
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