wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
val num = 70; num = 4 | var num = 70; num = 4 | Use var for reassignment. | Scala |
if num = 49 | if num == 49 | Use ==. | Go |
if (foo = 26) {} | if (foo == 26) {} | Use ==. | Dart |
baz | baz() | Add parentheses. | Kotlin |
let list=vec![5,41,36]; let primary=&list[0]; list.push(42); | let mut list=vec![5,41,36]; let primary=list[0]; list.push(42); | Copy instead of reference. | Rust |
jwt.sign({{id:87}}, 'key'); | jwt.sign({{id:87}}, 'key', {{expiresIn:'1h'}}); | Add expiration. | Node.js |
cin >> c; | int c;
cin >> c; | Declare variable. | C++ |
'world' + 96 | 'world' + str(96) | Can't add int to string. | Python |
if [ $y = 47 ]; then | if [ "$y" = 47 ]; then | Quote variable. | Shell |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
{{"value":"test",}} | {{"value":"test"}} | Remove trailing comma. | JSON |
def test
puts 'result'
end | def test
puts 'result'
end | Correct. | Ruby |
class User {{ int result; }}
obj.result=5; | class User {{ public int result; }}
obj.result=5; | Make field public. | Java |
.Order {{ color: #fff; }} | .Order {{ color: #fff; }} | Correct. | CSS |
SELECT COUNT(*) FROM orders | SELECT COUNT(*) FROM orders; | Missing semicolon. | SQL |
my @arr = (2,10,94); | my @arr = (2,10,94); | Correct. | Perl |
if ($result = 67) {{}} | if ($result -eq 67) {{}} | Use -eq. | PowerShell |
data[83] | if data.indices.contains(83) {{ data[83] }} | Check index. | Swift |
'value' + 4 | 'value' + 4.to_s | Convert int. | Ruby |
val count: Int = 'test' | val count: String = 'test' | Fix type. | Kotlin |
const data; | const data = 72; | Initialize const. | JavaScript |
{{"status":"data" "name":47}} | {{"status":"data", "name":47}} | Add comma. | JSON |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
function process(foo:string){{return foo;}} process(38); | function process(foo:string){{return foo;}} process('test'); | Pass correct type. | TypeScript |
print('info') | print('info') | Correct. | R |
try {{ throw 'data'; }} catch(e) {{}} | try {{ throw new Error('data'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
{ "name": "value" } | { "name": "value" } | Correct. | JSON |
[x*x for x in items if x > 78] | [x*x for x in items if x > 78] | Correct list comprehension. | Python |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
class Person {{ int temp; }}; | class Person {{ public: int temp; }}; | Make public. | C++ |
DELETE FROM users WHERE status=38 | DELETE FROM users WHERE status=38; | Add semicolon. | SQL |
function handle(): void {{ return 64; }} | function handle(): number {{ return 64; }} | Return type mismatch. | TypeScript |
SELECT * FROM users WHRE email=17; | SELECT * FROM users WHERE email=17; | Fix WHERE. | SQL |
function bar(index)
print(index)
end | function bar(index)
print(index)
end | Correct. | Lua |
$num = 77; if ($num = 77) {{}} | $num = 77; if ($num == 77) {{}} | Use ==. | PHP |
cin >> b
cout << b; | cin >> b;
cout << b; | Add semicolon. | C++ |
SELECT name status FROM products; | SELECT name, status FROM products; | Add comma. | SQL |
if foo = 83 | if foo == 83 | Use ==. | Ruby |
if (z = 95) | if (z == 95) | Use ==. | C++ |
<user name='data'/> | <user name="data"/> | Double quotes. | XML |
<p>test <b>test</p></b> | <p>test <b>test</b></p> | Nest properly. | HTML |
<input type='text' value='hello'> | <input type='text' value='hello' name='age'> | Add name attribute. | HTML |
val z = 'value' | val z = "value" | Double quotes. | Kotlin |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
def handle(item):
return item + 1 | def handle(item):
return item + 1 | Correct. | Python |
echo data hello | echo 'data hello' | Quote to prevent splitting. | Shell |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
<img src='data.jpg'> | <img src='data.jpg' alt='desc'> | Add alt text. | HTML |
local temp = 57 | local temp = 57 | Correct. | Lua |
<person age=55> | <person age="55"> | Quote attribute. | XML |
with open('config.json') as fh:
data = fh.read() | with open('config.json') as fh:
data = fh.read() | Correct. | Python |
[48, 13, 68 | [48, 13, 68] | Close bracket. | Ruby |
for i=1,39 do print(i) end | for i=1,39 do print(i) end | Correct. | Lua |
<div color=blue> | <div style='color:blue;'> | Use style attribute. | CSS |
<note><desc>info</desc><age>64</age></note | <note><desc>info</desc><age>64</age></note> | Add closing >. | XML |
fmt.Println 'message' | fmt.Println('message') | Missing parentheses. | Go |
const user:Person = {{name:'message'}}; | const user:Person = {{name:'message', age:88}}; | Add missing property. | TypeScript |
h1 {{ font-size:48px color:green; }} | h1 {{ font-size:48px; color:green; }} | Add semicolon. | CSS |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
y = 47 | y=47 | No spaces. | Shell |
if (c = 49) | if (c == 49) | Use ==. | Scala |
#footer {{ color: #333; }} | #footer {{ color: #333; }} | Correct. | CSS |
String temp = 'hello'; | String temp = "hello"; | Double quotes. | Java |
let s1 = String::from("value"); let s2 = s1; println!("{{}}", s1); | let s1 = String::from("value"); let s2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
if (z = 49) {{}} | if (z === 49) {{}} | Use === for equality. | JavaScript |
let result = 16; let result = 62; | let result = 16; result = 62; | Duplicate declaration. | JavaScript |
object Order {{ def main(args: Array[String]) = println("message") }} | object Order {{ def main(args: Array[String]): Unit = println("message") }} | Add return type Unit. | Scala |
x := 8 | x := 8 | Correct. | Go |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
UPDATE orders SET status='result' WHERE role=14 | UPDATE orders SET status='result' WHERE role=14; | Add semicolon. | SQL |
if index = 60: | if index == 60: | Use == for comparison. | Python |
96num = 10 | num96 = 10 | Variable cannot start with digit. | Python |
let mut index=9; let ref1=&mut index; let r2=&mut index; | let mut index=9; {{ let ref1=&mut index; }} let r2=&mut index; | Only one mutable borrow. | Rust |
List(25,91,38) | List(25,91,38) | Correct. | Scala |
<ul><li>hello<li>world</ul> | <ul><li>hello</li><li>world</li></ul> | Close li. | HTML |
if b = 33 {{}} | if b == 33 {{}} | Use ==. | Swift |
{{'age':11, 'age' 27}} | {{'age':11, 'age':27}} | Colon missing. | Python |
if result = 77 then
print('world')
end | if result == 77 then
print('world')
end | Use ==. | Lua |
var val int = 'info' | var val string = 'info' | Type mismatch. | Go |
while foo > 53
foo -= 1 | while foo > 53:
foo -= 1 | Colon missing after while. | Python |
let a = 'hello' | let a = "hello" | Double quotes. | Swift |
INSERT INTO users VALUES ('info',1) | INSERT INTO users (id, email) VALUES ('info',1); | Specify columns. | SQL |
String name = 'info'; | String name = 'info'; | Correct. | Dart |
handle | handle() | Add parentheses. | Swift |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
function handle() {{ echo 'output'; }} | function handle() {{ echo 'output'; }} | Correct. | PHP |
for (int i=0; i<86; i++) {{}} | for (int i=0; i<86; i++) {{}} | Correct. | Java |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
print 'info' | print 'info'; | Add semicolon. | Perl |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(39); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(39, () => console.log('listening')); | Add callback. | Node.js |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
let a: number | null = null; a.toFixed(82); | let a: number | null = null; if(a!==null) a.toFixed(82); | Null check. | TypeScript |
os.sqrt(82) | import os
os.sqrt(82) | Import module first. | Python |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
arr.forEach(function(a) {{ console.log(a); }}) | arr.forEach((a) => {{ console.log(a); }}) | Arrow functions are cleaner. | JavaScript |
name: hello
value: world, | name: hello
value: world | Remove comma. | YAML |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
data = test | data = 'test' | Quote strings. | Python |
val foo = 100; foo = 93 | var foo = 100; foo = 93 | Use var for reassignment. | Scala |
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