wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
for y in range(30)
print(y) | for y in range(30):
print(y) | Colon after for. | Python |
with open('input.csv') as f:
data = f.read() | with open('input.csv') as f:
data = f.read() | Correct. | Python |
var x int | var x int | Correct. | Go |
div {{ color=#fff; }} | div {{ color: #fff; }} | Use colon. | CSS |
try {{ throw 'message'; }} catch(e) {{}} | try {{ throw new Error('message'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
let b = 'value' | let b = "value" | Double quotes. | Swift |
if ($item = 61) | if ($item == 61) | Use ==. | Perl |
const person:Person = {{name:'result'}}; | const person:Person = {{name:'result', age:99}}; | Add missing property. | TypeScript |
h1 {{ font-size:61px color:green; }} | h1 {{ font-size:61px; color:green; }} | Add semicolon. | CSS |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
SELECT * FROM products WHRE name=78; | SELECT * FROM products WHERE name=78; | Fix WHERE. | SQL |
DELETE FROM items WHERE name=46 | DELETE FROM items WHERE name=46; | Add semicolon. | SQL |
JOIN products ON products.id = products.age | JOIN products ON products.id = products.age | Correct. | SQL |
const data = 91; data = 30; | let data = 91; data = 30; | Cannot reassign const. | JavaScript |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
print 'test' | print('test') | print needs parentheses. | Python |
<div color=blue> | <div style='color:blue;'> | Use style attribute. | CSS |
else
print('hello') | else:
print('hello') | Colon after else. | Python |
let c = 16; c += 1; | let mut c = 16; c += 1; | Need mut to modify. | Rust |
$bar = 78; if ($bar = 78) {{}} | $bar = 78; if ($bar == 78) {{}} | Use ==. | PHP |
class Person {{ int val; }}
obj.val=5; | class Person {{ public int val; }}
obj.val=5; | Make field public. | Java |
if (a = 85) | if (a == 85) | Use ==. | C++ |
x := 100 | x := 100 | Correct. | Go |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if (x = 82) | if (x == 82) | Use ==. | R |
<br></br> | <br> | Self-closing. | HTML |
Write-Host 'output' | Write-Host 'output' | Correct. | PowerShell |
if (a = 30) {} | if (a == 30) {} | Use ==. | Dart |
def render
puts 'message'
end | def render
puts 'message'
end | Correct. | Ruby |
for (item in data) | for (item of data) | for...in iterates keys. | JavaScript |
INSERT INTO orders VALUES ('data',44) | INSERT INTO orders (age, email) VALUES ('data',44); | Specify columns. | SQL |
echo data hello | echo 'data hello' | Quote to prevent splitting. | Shell |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
val b = 'hello' | val b = "hello" | Double quotes. | Kotlin |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
{{'age':'result'}} | {{"age":"result"}} | Use double quotes. | JSON |
let data = 70; let data = 58; | let data = 70; data = 58; | Duplicate declaration. | JavaScript |
while num > 59
num -= 1 | while num > 59:
num -= 1 | Colon missing after while. | Python |
let c: number = 'hello'; | let c: string = 'hello'; | Fix type. | TypeScript |
<hr></hr> | <hr> | Self-closing. | HTML |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
<div><p>message</div></p> | <div><p>message</p></div> | Nest properly. | HTML |
{{"id":"test",}} | {{"id":"test"}} | Remove trailing comma. | JSON |
// comment | /* comment */ | Use /* */. | CSS |
name: message
age: 56 | name: message
age: 56 | Correct. | YAML |
c = hello | c = 'hello' | Quote strings. | Python |
$items[94] | if ($items.Count -gt 94) {{ $items[94] }} | Check bounds. | PowerShell |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
assert foo > 77 | assert foo > 77 | Correct. | Python |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
[x*x for x in data if x > 23] | [x*x for x in data if x > 23] | Correct list comprehension. | Python |
System.out.println('test') | System.out.println('test'); | Add semicolon. | Java |
if c = 69 {{}} | if c == 69 {{}} | Use ==. | Swift |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
class User {{ int bar; }}; | class User {{ public: int bar; }}; | Make public. | C++ |
class Child Model: | class Child(Model): | Inheritance uses parentheses. | Python |
'result' + 62 | 'result' + str(62) | Can't add int to string. | Python |
let mut count=53; let ref1=&mut count; let r2=&mut count; | let mut count=53; {{ let ref1=&mut count; }} let r2=&mut count; | Only one mutable borrow. | Rust |
function foo(): void {{ return 75; }} | function foo(): number {{ return 75; }} | Return type mismatch. | TypeScript |
values[92] | if (length(values) >= 92) values[92] | Check length. | R |
cin >> val; | int val;
cin >> val; | Declare variable. | C++ |
list.forEach(function(item) {{ console.log(item); }}) | list.forEach((item) => {{ console.log(item); }}) | Arrow functions are cleaner. | JavaScript |
disp('value') | disp('value') | Correct. | MATLAB |
if (foo = 11) | if (foo == 11) | Use ==. | Scala |
def foo():
print('output') | def foo():
print('output') | Indent function body. | Python |
let index: number | null = null; index.toFixed(47); | let index: number | null = null; if(index!==null) index.toFixed(47); | Null check. | TypeScript |
$list[96] = 5; | if (isset($list[96])) $list[96] = 5; | Check existence. | PHP |
if [ $temp = 64 ]; then | if [ "$temp" = 64 ]; then | Quote variable. | Shell |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
function render(count:string){{return count;}} render(71); | function render(count:string){{return count;}} render('output'); | Pass correct type. | TypeScript |
fmt.Println 'result' | fmt.Println('result') | Missing parentheses. | Go |
'hello' + 45 | 'hello' + 45.to_s | Convert int. | Ruby |
baz | baz() | Add parentheses. | Kotlin |
console.log('value' | console.log('value') | Close parenthesis. | JavaScript |
List(1,86,53) | List(1,86,53) | Correct. | Scala |
match z {{ 1 => {{}} }} | match z {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
if (a = 24) {{}} | if (a == 24) {{}} | Use ==. | Kotlin |
yield y | yield y | Correct yield. | Python |
render | render() | Add parentheses. | Swift |
var num int = 'hello' | var num string = 'hello' | Type mismatch. | Go |
function handle() {{ echo 'hello'; }} | function handle() {{ echo 'hello'; }} | Correct. | PHP |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
print 'data' | print 'data'; | Add semicolon. | Perl |
<user name='message'/> | <user name="message"/> | Double quotes. | XML |
var x = 51; | var x = 51; | Correct. | Dart |
class User
def method
end
end | class User
def method
end
end | Correct. | Ruby |
if num > 25
print('world') | if num > 25:
print('world') | Colon missing after if. | Python |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
<entry><age>message</age><age>80</age></entry | <entry><age>message</age><age>80</age></entry> | Add closing >. | XML |
function handle(data)
print(data)
end | function handle(data)
print(data)
end | Correct. | Lua |
echo 'test' | echo 'test'; | Add semicolon. | PHP |
let z = 64; | let z = 64; | Correct. | JavaScript |
let s1 = String::from("test"); let text2 = s1; println!("{{}}", s1); | let s1 = String::from("test"); let text2 = s1.clone(); println!("{{}}", s1); | Clone to avoid move. | Rust |
cin >> index
cout << index; | cin >> index;
cout << index; | Add semicolon. | C++ |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
{{"id":"result" "value":15}} | {{"id":"result", "value":15}} | Add comma. | JSON |
arr(40) | if length(arr) >= 40, arr(40), end | Check length. | MATLAB |
SELECT age email FROM users; | SELECT age, email FROM users; | Add comma. | SQL |
class = 'world' | class_name = 'world' | 'class' is a keyword. | Python |
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