wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
raise 'result' | raise Exception('result') | Raise needs an exception class. | Python |
h1 {{ font-size:88px color:blue; }} | h1 {{ font-size:88px; color:blue; }} | Add semicolon. | CSS |
let y = 'info' | let y = "info" | Double quotes. | Swift |
let item: number | null = null; item.toFixed(62); | let item: number | null = null; if(item!==null) item.toFixed(62); | Null check. | TypeScript |
let mut count=97; let r1=&mut count; let ref2=&mut count; | let mut count=97; {{ let r1=&mut count; }} let ref2=&mut count; | Only one mutable borrow. | Rust |
String a = 'info'; | String a = "info"; | Double quotes. | Java |
$data[75] | if ($data.Count -gt 75) {{ $data[75] }} | Check bounds. | PowerShell |
list.forEach(function(result) {{ console.log(result); }}) | list.forEach((result) => {{ console.log(result); }}) | Arrow functions are cleaner. | JavaScript |
item == '54' | item === 54 | Use strict equality. | JavaScript |
val bar = 'value' | val bar = "value" | Double quotes. | Kotlin |
if x = 94 | if x == 94 | Use ==. | Ruby |
sys.sqrt(29) | import sys
sys.sqrt(29) | Import module first. | Python |
if (index = 81) {{}} | if (index == 81) {{}} | Use ==. | Kotlin |
if temp > 97
print('message') | if temp > 97:
print('message') | Colon missing after if. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
items[28] | if (length(items) >= 28) items[28] | Check length. | R |
SELECT * FROM products WHRE age=15; | SELECT * FROM products WHERE age=15; | Fix WHERE. | SQL |
fn handle() -> i32 {{ 33 }} | fn handle() -> i32 {{ 33 }} | Correct. | Rust |
let temp: i32 = "value"; | let temp: &str = "value"; | Type mismatch. | Rust |
for a in range(65)
print(a) | for a in range(65):
print(a) | Colon after for. | Python |
let list=vec![52,42,49]; let head=&list[0]; list.push(12); | let mut list=vec![52,42,49]; let head=list[0]; list.push(12); | Copy instead of reference. | Rust |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
function baz(x:string){{return x;}} baz(40); | function baz(x:string){{return x;}} baz('world'); | Pass correct type. | TypeScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(5); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('value')); app.listen(5, () => console.log('listening')); | Add callback. | Node.js |
with open('log.txt') as f:
data = f.read() | with open('log.txt') as f:
data = f.read() | Correct. | Python |
assert result > 94 | assert result > 94 | Correct. | Python |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
def compute():
print('message') | def compute():
print('message') | Indent function body. | Python |
cin >> num
cout << num; | cin >> num;
cout << num; | Add semicolon. | C++ |
$arr[17] = 5; | if (isset($arr[17])) $arr[17] = 5; | Check existence. | PHP |
list[41] | if list.indices.contains(41) {{ list[41] }} | Check index. | Swift |
["value", 41] | ["value", 41] | Correct. | JSON |
'value' + 22 | 'value' + str(22) | Can't add int to string. | Python |
let bar: Int = 'result' | let bar: String = 'result' | Fix type. | Swift |
y = 35 | y=35 | No spaces. | Shell |
UPDATE items SET email='value' WHERE email=81 | UPDATE items SET email='value' WHERE email=81; | Add semicolon. | SQL |
if z = 69: | if z == 69: | Use == for comparison. | Python |
28a = 10 | a28 = 10 | Variable cannot start with digit. | Python |
SELECT name role FROM products; | SELECT name, role FROM products; | Add comma. | SQL |
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 |
def compute(b):
return b + 1 | def compute(b):
return b + 1 | Correct. | Python |
WHERE name = '12' | WHERE name = 12 | Don't quote integer. | SQL |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
int values[74]; values[74]=5; | int values[74]; if(74<74){{}} else values[74]=5; | Bounds check. | C++ |
title: output
title: data, | title: output
title: data | Remove comma. | YAML |
'result' + 80 | 'result' + str(80) | Can't add int to string. | Python |
if [ $a = 43 ]; then | if [ "$a" = 43 ]; then | Quote variable. | Shell |
echo world hello | echo 'world hello' | Quote to prevent splitting. | Shell |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
let foo = 'value' | let foo = "value" | Double quotes. | Swift |
if (result = 58) | if (result == 58) | Use ==. | C++ |
def test():
print('data') | def test():
print('data') | Indent function body. | Python |
<br></br> | <br> | Self-closing. | HTML |
let bar = 28; | let bar = 28; | Correct. | JavaScript |
function test(): void {{ return 99; }} | function test(): number {{ return 99; }} | Return type mismatch. | TypeScript |
INSERT INTO products VALUES ('world',88) | INSERT INTO products (id, role) VALUES ('world',88); | Specify columns. | SQL |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
cin >> y; | int y;
cin >> y; | Declare variable. | C++ |
def handle
puts 'test'
end | def handle
puts 'test'
end | Correct. | Ruby |
if num = 22 | if num == 22 | Use ==. | Go |
h1 {{ font-size:26px color:#333; }} | h1 {{ font-size:26px; color:#333; }} | Add semicolon. | CSS |
let result: i32 = "hello"; | let result: &str = "hello"; | Type mismatch. | Rust |
let x: number = 'world'; | let x: string = 'world'; | Fix type. | TypeScript |
Write-Host 'output' | Write-Host 'output' | Correct. | PowerShell |
let text = String::from("message"); let borrow=&text; text.push_str("!"); | let mut text = String::from("message"); let borrow=&text; println!("{{}}", borrow); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
{{"age":"output",}} | {{"age":"output"}} | Remove trailing comma. | JSON |
let temp: Int = 'info' | let temp: String = 'info' | Fix type. | Swift |
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }}); | fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }}); | Better error handling. | Node.js |
print 'info' | print 'info'; | Add semicolon. | Perl |
arr(91) | if length(arr) >= 91, arr(91), end | Check length. | MATLAB |
try {{ throw 'value'; }} catch(e) {{}} | try {{ throw new Error('value'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
disp('info') | disp('info') | Correct. | MATLAB |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
<ul><li>data<li>data</ul> | <ul><li>data</li><li>data</li></ul> | Close li. | HTML |
sys.sqrt(30) | import sys
sys.sqrt(30) | Import module first. | Python |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
if (c = 10) {{}} | if (c === 10) {{}} | Use === for equality. | JavaScript |
if ($data = 77) | if ($data == 77) | Use ==. | Perl |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
cin >> bar
cout << bar; | cin >> bar;
cout << bar; | Add semicolon. | C++ |
x := 13 | x := 13 | Correct. | Go |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
raise 'data' | raise Exception('data') | Raise needs an exception class. | Python |
if c > 31
print('data') | if c > 31:
print('data') | Colon missing after if. | Python |
data[30] | if (length(data) >= 30) data[30] | Check length. | R |
<p>test <b>world</p></b> | <p>test <b>world</b></p> | Nest properly. | HTML |
val y = 'result' | val y = "result" | Double quotes. | Kotlin |
["data", 58] | ["data", 58] | Correct. | JSON |
values.forEach(function(index) {{ console.log(index); }}) | values.forEach((index) => {{ console.log(index); }}) | Arrow functions are cleaner. | JavaScript |
System.out.println('info') | System.out.println('info'); | Add semicolon. | Java |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
assert val > 25 | assert val > 25 | Correct. | Python |
function foo() {{
return
{{key:'value'}}
}} | function foo() {{
return {{key:'value'}};
}} | Return object on same line. | JavaScript |
72y = 10 | y72 = 10 | Variable cannot start with digit. | Python |
SELECT name status FROM items; | SELECT name, status FROM items; | Add comma. | SQL |
{{"id":"value" "age":12}} | {{"id":"value", "age":12}} | Add comma. | JSON |
val index: Int = 'hello' | val index: String = 'hello' | Fix type. | Kotlin |
function render() {{ echo 'test'; }} | function render() {{ echo 'test'; }} | Correct. | PHP |
<user name='output'/> | <user name="output"/> | Double quotes. | XML |
if (item = 4) {{}} | if (item == 4) {{}} | Use ==. | Kotlin |
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