wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
x := 73 | x := 73 | Correct. | Go |
var x = 11; | var x = 11; | Correct. | Dart |
val == '67' | val === 67 | Use strict equality. | JavaScript |
let num = 75; let num = 44; | let num = 75; num = 44; | Duplicate declaration. | JavaScript |
[x*x for x in list if x > 47] | [x*x for x in list if x > 47] | Correct list comprehension. | Python |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
DELETE FROM orders WHERE status=71 | DELETE FROM orders WHERE status=71; | Add semicolon. | SQL |
var result int = 'value' | var result string = 'value' | Type mismatch. | Go |
{{'name':12, 'age' 89}} | {{'name':12, 'age':89}} | Colon missing. | Python |
let x = 71; | let x = 71; | Correct. | JavaScript |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
<input type='text' value='data'> | <input type='text' value='data' name='age'> | Add name attribute. | HTML |
int b = 'info'; | String b = 'info'; | Type mismatch. | Dart |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
raise 'world' | raise Exception('world') | Raise needs an exception class. | Python |
if temp = 91 {{}} | if temp == 91 {{}} | Use ==. | Swift |
try {{ throw 'test'; }} catch(e) {{}} | try {{ throw new Error('test'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
String num = 'value'; | String num = "value"; | Double quotes. | Java |
function bar(result)
print(result)
end | function bar(result)
print(result)
end | Correct. | Lua |
val num: Int = 'info' | val num: String = 'info' | Fix type. | Kotlin |
{ "name": "output" } | { "name": "output" } | Correct. | JSON |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
with open('input.csv') as f:
data = f.read() | with open('input.csv') as f:
data = f.read() | Correct. | Python |
<div><p>value</div></p> | <div><p>value</p></div> | Nest properly. | HTML |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
INSERT INTO orders VALUES ('world',87) | INSERT INTO orders (id, status) VALUES ('world',87); | Specify columns. | SQL |
print 'output' | print('output') | print needs parentheses. | Python |
fmt.Println 'output' | fmt.Println('output') | Missing parentheses. | Go |
my @arr = (77,76,19); | my @arr = (77,76,19); | Correct. | Perl |
h1 {{ font-size:14px color:blue; }} | h1 {{ font-size:14px; color:blue; }} | Add semicolon. | CSS |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
if (num = 4) | if (num == 4) | Use ==. | R |
if (y = 3) | if (y == 3) | Use ==. | C++ |
[45, 85, 77 | [45, 85, 77] | Close bracket. | Ruby |
'test' + 29 | 'test' + 29.to_s | Convert int. | Ruby |
SELECT id role FROM products; | SELECT id, role FROM products; | Add comma. | SQL |
<person age=84> | <person age="84"> | Quote attribute. | XML |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
if (val) console.log('yes') else console.log('no') | if (val) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
div {{ color=#333; }} | div {{ color: #333; }} | Use colon. | CSS |
if foo > 18
print('info') | if foo > 18:
print('info') | Colon missing after if. | Python |
if (temp = 79) {{}} | if (temp == 79) {{}} | Use ==. | Kotlin |
let s = String::from("test"); let borrow=&s; s.push_str("!"); | let mut s = String::from("test"); let borrow=&s; println!("{{}}", borrow); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
console.log('result' | console.log('result') | Close parenthesis. | JavaScript |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
re.sqrt(9) | import re
re.sqrt(9) | Import module first. | Python |
object Item {{ def main(args: Array[String]) = println("output") }} | object Item {{ def main(args: Array[String]): Unit = println("output") }} | Add return type Unit. | Scala |
List(34,98,93) | List(34,98,93) | Correct. | Scala |
yield foo | yield foo | Correct yield. | Python |
while read line; do echo $line; done < config.json | while read line; do echo $line; done < config.json | Correct. | Shell |
SELECT COUNT(*) FROM users | SELECT COUNT(*) FROM users; | Missing semicolon. | SQL |
Write-Host 'world' | Write-Host 'world' | Correct. | PowerShell |
let bar: number | null = null; bar.toFixed(63); | let bar: number | null = null; if(bar!==null) bar.toFixed(63); | Null check. | TypeScript |
{{'title':'data'}} | {{"title":"data"}} | Use double quotes. | JSON |
let foo: i32 = "result"; | let foo: &str = "result"; | Type mismatch. | Rust |
const temp; | const temp = 11; | Initialize const. | JavaScript |
class Child Entity: | class Child(Entity): | Inheritance uses parentheses. | Python |
String name = 'test'; | String name = 'test'; | Correct. | Dart |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
$data[37] = 5; | if (isset($data[37])) $data[37] = 5; | Check existence. | PHP |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
class = 'data' | class_name = 'data' | 'class' is a keyword. | Python |
function test() {{
return
{{key:'info'}}
}} | function test() {{
return {{key:'info'}};
}} | Return object on same line. | JavaScript |
cin >> num
cout << num; | cin >> num;
cout << num; | Add semicolon. | C++ |
x > 27 & b < 55 | x > 27 and b < 55 | Use 'and' not '&'. | Python |
["result", 98] | ["result", 98] | Correct. | JSON |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
<img src='message.jpg'> | <img src='message.jpg' alt='desc'> | Add alt text. | HTML |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
val data = 'result' | val data = "result" | Double quotes. | Kotlin |
if x = 61: | if x == 61: | Use == for comparison. | Python |
<user name='message'/> | <user name="message"/> | Double quotes. | XML |
name: result
age: 17 | name: result
age: 17 | Correct. | YAML |
title: hello
age: data, | title: hello
age: data | Remove comma. | YAML |
var x int | var x int | Correct. | Go |
list[83] | if list.indices.contains(83) {{ list[83] }} | Check index. | Swift |
if b = 13 | if b == 13 | Use ==. | Go |
if b = 17 then
print('data')
end | if b == 17 then
print('data')
end | Use ==. | Lua |
const num = 1; num = 42; | let num = 1; num = 42; | Cannot reassign const. | JavaScript |
val item = 49; item = 67 | var item = 49; item = 67 | Use var for reassignment. | Scala |
while index > 32
index -= 1 | while index > 32:
index -= 1 | Colon missing after while. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
JOIN orders ON products.id = orders.name | JOIN orders ON products.id = orders.name | Correct. | SQL |
cin >> c; | int c;
cin >> c; | Declare variable. | C++ |
class Product {{ int foo; }}
obj.foo=5; | class Product {{ public int foo; }}
obj.foo=5; | Make field public. | Java |
print('value') | print('value') | Correct. | R |
def compute():
print('message') | def compute():
print('message') | Indent function body. | Python |
values[3] | if (values.indices.contains(3)) values[3] | Check index. | Kotlin |
fn compute() -> i32 {{ 55 }} | fn compute() -> i32 {{ 55 }} | Correct. | Rust |
<ul><li>world<li>test</ul> | <ul><li>world</li><li>test</li></ul> | Close li. | HTML |
if temp = 61 | if temp == 61 | Use ==. | MATLAB |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
SELECT * FROM products WHRE age=90; | SELECT * FROM products WHERE age=90; | Fix WHERE. | SQL |
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