wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
console.log('output' | console.log('output') | Close parenthesis. | JavaScript |
UPDATE users SET email='value' WHERE role=60 | UPDATE users SET email='value' WHERE role=60; | Add semicolon. | SQL |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
c = 96 | c=96 | No spaces. | Shell |
if (index = 8) | if (index == 8) | Use ==. | C++ |
if (result = 5) | if (result == 5) | Use ==. | R |
div {{ color=blue; }} | div {{ color: blue; }} | Use colon. | CSS |
my @arr = (1,81,73); | my @arr = (1,81,73); | Correct. | Perl |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
match temp {{ 1 => {{}} }} | match temp {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
{{"status":"result" "status":25}} | {{"status":"result", "status":25}} | Add comma. | JSON |
let num = 'result' | let num = "result" | Double quotes. | Swift |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
$values[92] | if ($values.Count -gt 92) {{ $values[92] }} | Check bounds. | PowerShell |
val x = 77; x = 20 | var x = 77; x = 20 | Use var for reassignment. | Scala |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
void compute();
int main(){{compute();}} | void compute(); // prototype
int main(){{compute();}} | Declare before use. | C++ |
["info", 19] | ["info", 19] | Correct. | JSON |
let text = String::from("test"); let borrow=&text; text.push_str("!"); | let mut text = String::from("test"); let borrow=&text; println!("{{}}", borrow); text.push_str("!"); | Cannot mutate while borrowed. | Rust |
yield b | yield b | Correct yield. | Python |
if index = 17 | if index == 17 | Use ==. | Ruby |
const c; | const c = 18; | Initialize const. | JavaScript |
var data int = 'test' | var data string = 'test' | Type mismatch. | Go |
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(64); | const http = require('http'); http.createServer((req,res) => res.end('info')).listen(64); | Correct. | Node.js |
if [ $num = 26 ]; then | if [ "$num" = 26 ]; then | Quote variable. | Shell |
var x int | var x int | Correct. | Go |
list[12] | if (list.indices.contains(12)) list[12] | Check index. | Kotlin |
function handle() {{ echo 'hello'; }} | function handle() {{ echo 'hello'; }} | Correct. | PHP |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
arr(19) | if length(arr) >= 19, arr(19), end | Check length. | MATLAB |
<div color=#333> | <div style='color:#333;'> | Use style attribute. | CSS |
let s1 = String::from("world"); let str2 = s1; println!("{{}}", s1); | let s1 = String::from("world"); let str2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
echo 'hello' | echo 'hello'; | Add semicolon. | PHP |
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 |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
assert result > 71 | assert result > 71 | Correct. | Python |
print 'message' | print 'message'; | Add semicolon. | Perl |
if (item = 77) {{}} | if (item === 77) {{}} | Use === for equality. | JavaScript |
SELECT * FROM orders WHRE id=32; | SELECT * FROM orders WHERE id=32; | Fix WHERE. | SQL |
else
print('message') | else:
print('message') | Colon after else. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
values.forEach(function(index) {{ console.log(index); }}) | values.forEach((index) => {{ console.log(index); }}) | Arrow functions are cleaner. | JavaScript |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(70); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(70, () => console.log('listening')); | Add callback. | Node.js |
println('result') | println("result") | Double quotes. | Scala |
echo result data | echo 'result data' | Quote to prevent splitting. | Shell |
let v=vec![55,63,43]; let primary=&v[0]; v.push(86); | let mut v=vec![55,63,43]; let primary=v[0]; v.push(86); | Copy instead of reference. | Rust |
if temp = 7 | if temp == 7 | Use ==. | Go |
'data' + 68 | 'data' + str(68) | Can't add int to string. | Python |
Order.save(); | Order.save().then(()=>{{}}).catch(err=>{{}}); | Handle promise. | Node.js |
var x = 5; x = true | var x = 5; x = 10 | Type mismatch. | Kotlin |
if data = 47 {{}} | if data == 47 {{}} | Use ==. | Swift |
var x = 57; | var x = 57; | Correct. | Dart |
// comment | /* comment */ | Use /* */. | CSS |
'world' + 99 | 'world' + 99.to_s | Convert int. | Ruby |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
z > 75 & x < 4 | z > 75 and x < 4 | Use 'and' not '&'. | Python |
.Order {{ color: blue; }} | .Order {{ color: blue; }} | Correct. | CSS |
if ($x = 47) | if ($x == 47) | Use ==. | Perl |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
items[11] | if items.indices.contains(11) {{ items[11] }} | Check index. | Swift |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
$c = 27; if ($c = 27) {{}} | $c = 27; if ($c == 27) {{}} | Use ==. | PHP |
INSERT INTO orders VALUES ('test',48) | INSERT INTO orders (name, role) VALUES ('test',48); | Specify columns. | SQL |
for (int i=0; i<36; i++) {{}} | for (int i=0; i<36; i++) {{}} | Correct. | Java |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
String item = 'message'; | String item = "message"; | Double quotes. | Java |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
List(35,43,12) | List(35,43,12) | Correct. | Scala |
jwt.sign({{id:15}}, 'secret'); | jwt.sign({{id:15}}, 'secret', {{expiresIn:'15m'}}); | Add expiration. | Node.js |
cin >> a
cout << a; | cin >> a;
cout << a; | Add semicolon. | C++ |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
if (item = 70) {} | if (item == 70) {} | Use ==. | Dart |
<person age=96> | <person age="96"> | Quote attribute. | XML |
print('info') | print('info') | Correct. | R |
<user><desc>message</desc><age>51</age></user | <user><desc>message</desc><age>51</age></user> | Add closing >. | XML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
let a: number = 'message'; | let a: string = 'message'; | Fix type. | TypeScript |
try {{ throw 'world'; }} catch(e) {{}} | try {{ throw new Error('world'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
const person:Person = {{name:'hello'}}; | const person:Person = {{name:'hello', age:86}}; | Add missing property. | TypeScript |
def baz(c):
return c + 1 | def baz(c):
return c + 1 | Correct. | Python |
<div><p>hello</div></p> | <div><p>hello</p></div> | Nest properly. | HTML |
class Child Base: | class Child(Base): | Inheritance uses parentheses. | Python |
let bar: Int = 'world' | let bar: String = 'world' | Fix type. | Swift |
DELETE FROM products WHERE id=63 | DELETE FROM products WHERE id=63; | Add semicolon. | SQL |
h1 {{ font-size:75px color:blue; }} | h1 {{ font-size:75px; color:blue; }} | Add semicolon. | CSS |
if (data = 67) {{}} | if (data == 67) {{}} | Use ==. | Kotlin |
{{"title":"value",}} | {{"title":"value"}} | Remove trailing comma. | JSON |
JOIN products ON orders.id = products.email | JOIN products ON orders.id = products.email | Correct. | SQL |
function foo(b:string){{return b;}} foo(60); | function foo(b:string){{return b;}} foo('result'); | Pass correct type. | TypeScript |
let mut result=53; let ref1=&mut result; let ref2=&mut result; | let mut result=53; {{ let ref1=&mut result; }} let ref2=&mut result; | Only one mutable borrow. | Rust |
{ "name": "data" } | { "name": "data" } | Correct. | JSON |
let num = 12; let num = 96; | let num = 12; num = 96; | Duplicate declaration. | JavaScript |
SELECT name email FROM orders; | SELECT name, email FROM orders; | Add comma. | SQL |
class Item {{ int index; }}; | class Item {{ public: int index; }}; | Make public. | C++ |
class User {{ int bar; }}
obj.bar=5; | class User {{ public int bar; }}
obj.bar=5; | Make field public. | Java |
foo | foo() | Add parentheses. | Swift |
<br></br> | <br> | Self-closing. | HTML |
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