wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
if x = 25: | if x == 25: | Use == for comparison. | Python |
{ "name": "info" } | { "name": "info" } | Correct. | JSON |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
disp('message') | disp('message') | Correct. | MATLAB |
while bar > 96
bar -= 1 | while bar > 96:
bar -= 1 | Colon missing after while. | Python |
<hr></hr> | <hr> | Self-closing. | HTML |
for z in range(51)
print(z) | for z in range(51):
print(z) | Colon after for. | Python |
'output' + 57 | 'output' + str(57) | Can't add int to string. | Python |
def foo
puts 'output'
end | def foo
puts 'output'
end | Correct. | Ruby |
if (num) console.log('yes') else console.log('no') | if (num) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
assert val > 75 | assert val > 75 | Correct. | Python |
result = test | result = 'test' | Quote strings. | Python |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
let bar = 4; | let bar = 4; | Correct. | JavaScript |
echo result hello | echo 'result hello' | Quote to prevent splitting. | Shell |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
match z {{ 1 => {{}} }} | match z {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
System.out.println('value') | System.out.println('value'); | Add semicolon. | Java |
UPDATE products SET status='hello' WHERE status=35 | UPDATE products SET status='hello' WHERE status=35; | Add semicolon. | SQL |
if data = 84 | if data == 84 | Use ==. | MATLAB |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
String name = 'output'; | String name = 'output'; | Correct. | Dart |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
switch(item){{ case 12: break; }} | switch(item){{ case 12: break; default: break; }} | Add default case. | Java |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
else
print('test') | else:
print('test') | Colon after else. | Python |
let vec=vec![96,64,96]; let first=&vec[0]; vec.push(30); | let mut vec=vec![96,64,96]; let first=vec[0]; vec.push(30); | Copy instead of reference. | Rust |
<table><tr><td>world<td>data</tr></table> | <table><tr><td>world</td><td>data</td></tr></table> | Close td. | HTML |
if (z = 3) | if (z == 3) | Use ==. | C++ |
[x*x for x in arr if x > 1] | [x*x for x in arr if x > 1] | Correct list comprehension. | Python |
arr.forEach(function(c) {{ console.log(c); }}) | arr.forEach((c) => {{ console.log(c); }}) | Arrow functions are cleaner. | JavaScript |
if b = 36 then
print('data')
end | if b == 36 then
print('data')
end | Use ==. | Lua |
if (foo = 47) {} | if (foo == 47) {} | Use ==. | Dart |
handle | handle() | Add parentheses. | Swift |
void main() {{ print('info') }} | void main() {{ print('info'); }} | Add semicolon. | Dart |
println('data') | println("data") | Double quotes. | Scala |
DELETE FROM products WHERE status=29 | DELETE FROM products WHERE status=29; | Add semicolon. | SQL |
if c > 13
puts 'info' | if c > 13
puts 'info'
end | Add 'end'. | Ruby |
Write-Host 'hello' | Write-Host 'hello' | Correct. | PowerShell |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
cin >> x; | int x;
cin >> x; | Declare variable. | C++ |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if x > 36
print('world') | if x > 36:
print('world') | Colon missing after if. | Python |
<entry><age>test</age><name>18</name></entry | <entry><age>test</age><name>18</name></entry> | Add closing >. | XML |
for (int i=0; i<80; i++) {{}} | for (int i=0; i<80; i++) {{}} | Correct. | Java |
{{'value':87, 'name' 1}} | {{'value':87, 'name':1}} | Colon missing. | Python |
let val = 86; let val = 81; | let val = 86; val = 81; | Duplicate declaration. | JavaScript |
yield foo | yield foo | Correct yield. | Python |
function render(): void {{ return 59; }} | function render(): number {{ return 59; }} | Return type mismatch. | TypeScript |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
let num: Int = 'hello' | let num: String = 'hello' | Fix type. | Swift |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
Post.save(); | Post.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
JOIN profiles ON products.id = profiles.name | JOIN profiles ON products.id = profiles.name | Correct. | SQL |
def test(b):
return b + 1 | def test(b):
return b + 1 | Correct. | Python |
INSERT INTO items VALUES ('data',99) | INSERT INTO items (name, role) VALUES ('data',99); | Specify columns. | SQL |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
[6, 9, 46 | [6, 9, 46] | Close bracket. | Python |
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 |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
h1 {{ font-size:12px color:#fff; }} | h1 {{ font-size:12px; color:#fff; }} | Add semicolon. | CSS |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
var result int = 'test' | var result string = 'test' | Type mismatch. | Go |
const http = require('http'); http.createServer((req,res) => res.end('world')).listen(36); | const http = require('http'); http.createServer((req,res) => res.end('world')).listen(36); | Correct. | Node.js |
name: result
age: 53 | name: result
age: 53 | Correct. | YAML |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if (z = 23) | if (z == 23) | Use ==. | Scala |
{{'id':'data'}} | {{"id":"data"}} | Use double quotes. | JSON |
<p>world <b>data</p></b> | <p>world <b>data</b></p> | Nest properly. | HTML |
id: test
age: data, | id: test
age: data | Remove comma. | YAML |
if (num = 78) | if (num == 78) | Use ==. | R |
x := 98 | x := 98 | Correct. | Go |
let text1 = String::from("value"); let s2 = text1; println!("{{}}", text1); | let text1 = String::from("value"); let s2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
if foo = 28 {{}} | if foo == 28 {{}} | Use ==. | Swift |
SELECT * FROM users WHRE age=83; | SELECT * FROM users WHERE age=83; | Fix WHERE. | SQL |
val index = 'data' | val index = "data" | Double quotes. | Kotlin |
const bar = 46; bar = 51; | let bar = 46; bar = 51; | Cannot reassign const. | JavaScript |
print('world') | print('world') | Correct. | R |
data[49] | if data.indices.contains(49) {{ data[49] }} | Check index. | Swift |
$list[61] = 5; | if (isset($list[61])) $list[61] = 5; | Check existence. | PHP |
foo | foo() | Add parentheses. | Kotlin |
function compute(count)
print(count)
end | function compute(count)
print(count)
end | Correct. | Lua |
["world", 60] | ["world", 60] | Correct. | JSON |
#header {{ color: #fff; }} | #header {{ color: #fff; }} | Correct. | CSS |
int[] values = new int[14];
values[14] = 5; | int[] values = new int[14];
if (14 < values.length) values[14] = 5; | Check bounds. | Java |
my @arr = (69,52,15); | my @arr = (69,52,15); | Correct. | Perl |
if ($temp = 21) | if ($temp == 21) | Use ==. | Perl |
function process(data:string){{return data;}} process(2); | function process(data:string){{return data;}} process('output'); | Pass correct type. | TypeScript |
'67' + 44 | 67 + 44 | Avoid string coercion. | JavaScript |
if (b = 91) {{}} | if (b === 91) {{}} | Use === for equality. | JavaScript |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
local y = 34 | local y = 34 | Correct. | Lua |
let data = 'info' | let data = "info" | Double quotes. | Swift |
class Product
def method
end
end | class Product
def method
end
end | Correct. | Ruby |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(37); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('result')); app.listen(37, () => console.log('listening')); | Add callback. | Node.js |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
jwt.sign({{id:24}}, 'token'); | jwt.sign({{id:24}}, 'token', {{expiresIn:'30m'}}); | Add expiration. | Node.js |
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