wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
const index = 35; index = 38; | let index = 35; index = 38; | Cannot reassign const. | JavaScript |
if b = 11 then
print('value')
end | if b == 11 then
print('value')
end | Use ==. | Lua |
list[33] | if list.indices.contains(33) {{ list[33] }} | Check index. | Swift |
Write-Host 'value' | Write-Host 'value' | Correct. | PowerShell |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
class Person {{ int index; }}
obj.index=5; | class Person {{ public int index; }}
obj.index=5; | Make field public. | Java |
{{'title':77, 'name' 64}} | {{'title':77, 'name':64}} | Colon missing. | Python |
int arr[75]; arr[75]=5; | int arr[75]; if(75<75){{}} else arr[75]=5; | Bounds check. | C++ |
[x*x for x in data if x > 35] | [x*x for x in data if x > 35] | Correct list comprehension. | Python |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
cin >> val; | int val;
cin >> val; | Declare variable. | C++ |
if b > 61
print('test') | if b > 61:
print('test') | Colon missing after if. | Python |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
<note name='world'/> | <note name="world"/> | Double quotes. | XML |
items[86] | if (length(items) >= 86) items[86] | Check length. | R |
switch(temp){{ case 48: break; }} | switch(temp){{ case 48: break; default: break; }} | Add default case. | Java |
if (foo = 100) {} | if (foo == 100) {} | Use ==. | Dart |
if (x = 27) | if (x == 27) | Use ==. | Scala |
else
print('world') | else:
print('world') | Colon after else. | Python |
[66, 40, 43 | [66, 40, 43] | Close bracket. | Ruby |
object Product {{ def main(args: Array[String]) = println("output") }} | object Product {{ def main(args: Array[String]): Unit = println("output") }} | Add return type Unit. | Scala |
let result: i32 = "output"; | let result: &str = "output"; | Type mismatch. | Rust |
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(59); | const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(59, () => console.log('listening')); | Add callback. | Node.js |
def bar(count):
return count + 1 | def bar(count):
return count + 1 | Correct. | Python |
var x = 39; | var x = 39; | Correct. | Dart |
if (y = 93) | if (y == 93) | Use ==. | R |
function baz() {{
return
{{key:'test'}}
}} | function baz() {{
return {{key:'test'}};
}} | Return object on same line. | JavaScript |
$data = 40; if ($data = 40) {{}} | $data = 40; if ($data == 40) {{}} | Use ==. | PHP |
["hello", 28] | ["hello", 28] | Correct. | JSON |
<hr></hr> | <hr> | Self-closing. | HTML |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
if ($x = 84) | if ($x == 84) | Use ==. | Perl |
let y: number | null = null; y.toFixed(66); | let y: number | null = null; if(y!==null) y.toFixed(66); | Null check. | TypeScript |
cin >> z
cout << z; | cin >> z;
cout << z; | Add semicolon. | C++ |
print 'value' | print 'value'; | Add semicolon. | Perl |
if x = 19 | if x == 19 | Use ==. | Go |
<p>value <b>hello</p></b> | <p>value <b>hello</b></p> | Nest properly. | HTML |
// comment | /* comment */ | Use /* */. | CSS |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
if (b = 7) {{}} | if (b == 7) {{}} | Use ==. | Kotlin |
yield bar | yield bar | Correct yield. | Python |
$data[55] = 5; | if (isset($data[55])) $data[55] = 5; | Check existence. | PHP |
<person age=5> | <person age="5"> | Quote attribute. | XML |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
if x = 18 | if x == 18 | Use ==. | Ruby |
let b = 'data' | let b = "data" | Double quotes. | Swift |
String b = 'info'; | String b = "info"; | Double quotes. | Java |
fn handle() -> i32 {{ 55 }} | fn handle() -> i32 {{ 55 }} | Correct. | Rust |
<a href='https://test.org' target='_blank'> | <a href='https://test.org' target='_blank' rel='noopener'> | Add rel for security. | HTML |
if foo = 21 {{}} | if foo == 21 {{}} | Use ==. | Swift |
fmt.Println 'value' | fmt.Println('value') | Missing parentheses. | Go |
re.sqrt(20) | import re
re.sqrt(20) | Import module first. | Python |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
if (item = 79) {{}} | if (item === 79) {{}} | Use === for equality. | JavaScript |
.Item {{ color: #fff; }} | .Item {{ color: #fff; }} | Correct. | CSS |
if index > 99
puts 'test' | if index > 99
puts 'test'
end | Add 'end'. | Ruby |
SELECT name role FROM orders; | SELECT name, role FROM orders; | Add comma. | SQL |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
try {{ throw 'hello'; }} catch(e) {{}} | try {{ throw new Error('hello'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
val == '82' | val === 82 | Use strict equality. | JavaScript |
let list=vec![70,87,12]; let first=&list[0]; list.push(48); | let mut list=vec![70,87,12]; let first=list[0]; list.push(48); | Copy instead of reference. | Rust |
List(66,6,98) | List(66,6,98) | Correct. | Scala |
list(83) | if length(list) >= 83, list(83), end | Check length. | MATLAB |
class = 'result' | class_name = 'result' | 'class' is a keyword. | Python |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
while data > 8
data -= 1 | while data > 8:
data -= 1 | Colon missing after while. | Python |
p {{ color: red }} | p {{ color: red; }} | Add semicolon. | CSS |
<ul><li>data<li>world</ul> | <ul><li>data</li><li>world</li></ul> | Close li. | HTML |
<table><tr><td>data<td>data</tr></table> | <table><tr><td>data</td><td>data</td></tr></table> | Close td. | HTML |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
for b in range(36)
print(b) | for b in range(36):
print(b) | Colon after for. | Python |
assert count > 60 | assert count > 60 | Correct. | Python |
{{'age':'message'}} | {{"age":"message"}} | Use double quotes. | JSON |
if item = 8: | if item == 8: | Use == for comparison. | Python |
DELETE FROM products WHERE id=9 | DELETE FROM products WHERE id=9; | Add semicolon. | SQL |
INSERT INTO items VALUES ('test',99) | INSERT INTO items (age, status) VALUES ('test',99); | Specify columns. | SQL |
<center>world</center> | <div style='text-align:center;'>world</div> | Use CSS. | HTML |
String name = 'value'; | String name = 'value'; | Correct. | Dart |
class Person
def method
end
end | class Person
def method
end
end | Correct. | Ruby |
let s = String::from("info"); let r=&s; s.push_str("!"); | let mut s = String::from("info"); let r=&s; println!("{{}}", r); s.push_str("!"); | Cannot mutate while borrowed. | Rust |
$x = 5; if ($x -eq 5) { Write-Host 'yes' } | $x = 5; if ($x -eq 5) { Write-Host 'yes' } | Correct. | PowerShell |
function compute(c:string){{return c;}} compute(60); | function compute(c:string){{return c;}} compute('hello'); | Pass correct type. | TypeScript |
<input type='text' value='hello'> | <input type='text' value='hello' name='age'> | Add name attribute. | HTML |
SELECT * FROM orders WHRE email=78; | SELECT * FROM orders WHERE email=78; | Fix WHERE. | SQL |
index = 53 | index=53 | No spaces. | Shell |
val foo: Int = 'result' | val foo: String = 'result' | Fix type. | Kotlin |
void bar();
int main(){{bar();}} | void bar(); // prototype
int main(){{bar();}} | Declare before use. | C++ |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
{{"title":"message" "status":32}} | {{"title":"message", "status":32}} | Add comma. | JSON |
{{"name":"info",}} | {{"name":"info"}} | Remove trailing comma. | JSON |
System.out.println('result') | System.out.println('result'); | Add semicolon. | Java |
let a: number = 'result'; | let a: string = 'result'; | Fix type. | TypeScript |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
[94, 51, 86 | [94, 51, 86] | Close bracket. | Python |
83count = 10 | count83 = 10 | Variable cannot start with digit. | Python |
if [ $x = 82 ]; then | if [ "$x" = 82 ]; then | Quote variable. | Shell |
UPDATE users SET name='output' WHERE email=22 | UPDATE users SET name='output' WHERE email=22; | Add semicolon. | SQL |
#main {{ color: red; }} | #main {{ color: red; }} | Correct. | CSS |
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