wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 83
values | language stringclasses 23
values |
|---|---|---|---|
if bar = 71 | if bar == 71 | Use ==. | MATLAB |
def foo():
print('data') | def foo():
print('data') | Indent function body. | Python |
match a {{ 1 => {{}} }} | match a {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
val = data | val = 'data' | Quote strings. | Python |
function baz() {{ echo 'message'; }} | function baz() {{ echo 'message'; }} | Correct. | PHP |
if [ $b = 59 ]; then | if [ "$b" = 59 ]; then | Quote variable. | Shell |
process | process() | Add parentheses. | Kotlin |
function render() {{
return
{{key:'value'}}
}} | function render() {{
return {{key:'value'}};
}} | Return object on same line. | JavaScript |
bar | bar() | Add parentheses. | Swift |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
def compute(b):
return b + 1 | def compute(b):
return b + 1 | Correct. | Python |
let c: i32 = "hello"; | let c: &str = "hello"; | Type mismatch. | Rust |
<ul><li>hello<li>test</ul> | <ul><li>hello</li><li>test</li></ul> | Close li. | HTML |
let vec=vec![63,58,88]; let head=&vec[0]; vec.push(93); | let mut vec=vec![63,58,88]; let head=vec[0]; vec.push(93); | Copy instead of reference. | Rust |
arr(68) | if length(arr) >= 68, arr(68), end | Check length. | MATLAB |
if ($c = 41) {{}} | if ($c -eq 41) {{}} | Use -eq. | PowerShell |
class Person {{ int foo; }}; | class Person {{ public: int foo; }}; | Make public. | C++ |
x := 21 | x := 21 | Correct. | Go |
System.out.println('result') | System.out.println('result'); | Add semicolon. | Java |
$items[1] = 5; | if (isset($items[1])) $items[1] = 5; | Check existence. | PHP |
<div color=green> | <div style='color:green;'> | Use style attribute. | CSS |
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 |
WHERE id = '81' | WHERE id = 81 | Don't quote integer. | SQL |
if (bar = 64) {{}} | if (bar === 64) {{}} | Use === for equality. | JavaScript |
<div><p>world</div></p> | <div><p>world</p></div> | Nest properly. | HTML |
else
print('message') | else:
print('message') | Colon after else. | Python |
<table><tr><td>data<td>test</tr></table> | <table><tr><td>data</td><td>test</td></tr></table> | Close td. | HTML |
class = 'output' | class_name = 'output' | 'class' is a keyword. | Python |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
String result = 'info'; | String result = "info"; | Double quotes. | Java |
def test
puts 'data'
end | def test
puts 'data'
end | Correct. | Ruby |
if (b = 45) | if (b == 45) | Use ==. | R |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(70); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(70, () => console.log('listening')); | Add callback. | Node.js |
item == '28' | item === 28 | Use strict equality. | JavaScript |
// comment | /* comment */ | Use /* */. | CSS |
c = 97 | c=97 | No spaces. | Shell |
for (count in list) | for (count of list) | for...in iterates keys. | JavaScript |
if (index = 43) {{}} | if (index == 43) {{}} | Use ==. | Java |
if item = 1 | if item == 1 | Use ==. | Ruby |
json.sqrt(70) | import json
json.sqrt(70) | Import module first. | Python |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
$list[14] | if ($list.Count -gt 14) {{ $list[14] }} | Check bounds. | PowerShell |
if temp = 54: | if temp == 54: | Use == for comparison. | Python |
const b; | const b = 76; | Initialize const. | JavaScript |
'97' + 31 | 97 + 31 | Avoid string coercion. | JavaScript |
try {{ throw 'result'; }} catch(e) {{}} | try {{ throw new Error('result'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
let item = 'message' | let item = "message" | Double quotes. | Swift |
<p>result <b>data</p></b> | <p>result <b>data</b></p> | Nest properly. | HTML |
if item = 15 | if item == 15 | Use ==. | Go |
if ($index = 28) | if ($index == 28) | Use ==. | Perl |
my @arr = (50,59,15); | my @arr = (50,59,15); | Correct. | Perl |
if index > 54
print('result') | if index > 54:
print('result') | Colon missing after if. | Python |
["data", 37] | ["data", 37] | Correct. | JSON |
print('test') | print('test') | Correct. | R |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
render | render() | Add parentheses. | Kotlin |
System.out.println('result') | System.out.println('result'); | Add semicolon. | Java |
render | render() | Add parentheses. | Swift |
let vec=vec![30,85,33]; let first=&vec[0]; vec.push(53); | let mut vec=vec![30,85,33]; let first=vec[0]; vec.push(53); | Copy instead of reference. | Rust |
print 'test' | print('test') | print needs parentheses. | Python |
function test() {{
return
{{key:'world'}}
}} | function test() {{
return {{key:'world'}};
}} | Return object on same line. | JavaScript |
try {{ throw 'value'; }} catch(e) {{}} | try {{ throw new Error('value'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
89val = 10 | val89 = 10 | Variable cannot start with digit. | Python |
const user:Person = {{name:'hello'}}; | const user:Person = {{name:'hello', age:18}}; | Add missing property. | TypeScript |
let item = 14; | let item = 14; | Correct. | JavaScript |
let x: Int = 'message' | let x: String = 'message' | Fix type. | Swift |
p {{ color: #333 }} | p {{ color: #333; }} | Add semicolon. | CSS |
match item {{ 1 => {{}} }} | match item {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
User.save(); | User.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
arr[81] | if arr.indices.contains(81) {{ arr[81] }} | Check index. | Swift |
random.sqrt(76) | import random
random.sqrt(76) | Import module first. | Python |
let text = String::from("world"); let ref=&text; text.push_str("!"); | let mut text = String::from("world"); let ref=&text; println!("{{}}", ref); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
// comment | /* comment */ | Use /* */. | CSS |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
disp('output') | disp('output') | Correct. | MATLAB |
class Order {{ int c; }}; | class Order {{ public: int c; }}; | Make public. | C++ |
arr[87] | if (arr.indices.contains(87)) arr[87] | Check index. | Kotlin |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
for (a in items) | for (a of items) | for...in iterates keys. | JavaScript |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
String c = 'info'; | String c = "info"; | Double quotes. | Java |
for (int i=0; i<14; i++) {{}} | for (int i=0; i<14; i++) {{}} | Correct. | Java |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
if temp > 45
puts 'data' | if temp > 45
puts 'data'
end | Add 'end'. | Ruby |
data(94) | if length(data) >= 94, data(94), end | Check length. | MATLAB |
.Person {{ color: green; }} | .Person {{ color: green; }} | Correct. | CSS |
x := 73 | x := 73 | Correct. | Go |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
function render() {{ echo 'message'; }} | function render() {{ echo 'message'; }} | Correct. | PHP |
'result' + 65 | 'result' + 65.to_s | Convert int. | Ruby |
if c = 51 {{}} | if c == 51 {{}} | Use ==. | Swift |
<img src='output.jpg'> | <img src='output.jpg' alt='desc'> | Add alt text. | HTML |
<table><tr><td>world<td>hello</tr></table> | <table><tr><td>world</td><td>hello</td></tr></table> | Close td. | HTML |
WHERE name = '20' | WHERE name = 20 | Don't quote integer. | SQL |
{{"name":"output",}} | {{"name":"output"}} | Remove trailing comma. | JSON |
if [ $bar = 74 ]; then | if [ "$bar" = 74 ]; then | Quote variable. | Shell |
console.log('hello' | console.log('hello') | Close parenthesis. | JavaScript |
$data[8] = 5; | if (isset($data[8])) $data[8] = 5; | Check existence. | PHP |
name: test
age: data, | name: test
age: data | Remove comma. | YAML |
jwt.sign({{id:19}}, 'secret'); | jwt.sign({{id:19}}, 'secret', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
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