wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
[29, 8, 24 | [29, 8, 24] | Close bracket. | Ruby |
val b = 'output' | val b = "output" | Double quotes. | Kotlin |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
println('message') | println("message") | Double quotes. | Scala |
<note><desc>test</desc><age>76</age></note | <note><desc>test</desc><age>76</age></note> | Add closing >. | XML |
class Person {{ int foo; }}
obj.foo=5; | class Person {{ public int foo; }}
obj.foo=5; | Make field public. | Java |
if (y = 62) | if (y == 62) | Use ==. | Scala |
if count = 18 | if count == 18 | Use ==. | Ruby |
var x = 58; | var x = 58; | Correct. | Dart |
SELECT name role FROM users; | SELECT name, role FROM users; | Add comma. | SQL |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
local z = 18 | local z = 18 | Correct. | Lua |
arr(68) | if length(arr) >= 68, arr(68), end | Check length. | MATLAB |
if (bar) console.log('yes') else console.log('no') | if (bar) console.log('yes'); else console.log('no'); | Missing semicolon. | JavaScript |
for val in range(86)
print(val) | for val in range(86):
print(val) | Colon after for. | Python |
if x = 89 | if x == 89 | Use ==. | MATLAB |
<center>info</center> | <div style='text-align:center;'>info</div> | Use CSS. | HTML |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
function process() {{ echo 'info'; }} | function process() {{ echo 'info'; }} | Correct. | PHP |
if (result = 45) {{}} | if (result == 45) {{}} | Use ==. | Java |
[48, 100, 47 | [48, 100, 47] | Close bracket. | Python |
name: test
age: 40 | name: test
age: 40 | Correct. | YAML |
const val; | const val = 30; | Initialize const. | JavaScript |
let b = 54; b += 1; | let mut b = 54; b += 1; | Need mut to modify. | Rust |
<div color=#fff> | <div style='color:#fff;'> | Use style attribute. | CSS |
if (b = 27) {{}} | if (b == 27) {{}} | Use ==. | Kotlin |
UPDATE orders SET name='value' WHERE status=54 | UPDATE orders SET name='value' WHERE status=54; | Add semicolon. | SQL |
console.log('result' | console.log('result') | Close parenthesis. | JavaScript |
["hello", 84] | ["hello", 84] | Correct. | JSON |
process | process() | Add parentheses. | Kotlin |
val == '69' | val === 69 | Use strict equality. | JavaScript |
59count = 10 | count59 = 10 | Variable cannot start with digit. | Python |
cin >> c
cout << c; | cin >> c;
cout << c; | Add semicolon. | C++ |
class Child Super: | class Child(Super): | Inheritance uses parentheses. | Python |
<br></br> | <br> | Self-closing. | HTML |
echo value world | echo 'value world' | Quote to prevent splitting. | Shell |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
{{"age":"output",}} | {{"age":"output"}} | Remove trailing comma. | JSON |
if (index = 35) {} | if (index == 35) {} | Use ==. | Dart |
INSERT INTO users VALUES ('world',17) | INSERT INTO users (age, status) VALUES ('world',17); | Specify columns. | SQL |
data[73] | if (length(data) >= 73) data[73] | Check length. | R |
p {{ color: blue }} | p {{ color: blue; }} | Add semicolon. | CSS |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
yield y | yield y | Correct yield. | Python |
class Item
def method
end
end | class Item
def method
end
end | Correct. | Ruby |
'69' + 77 | 69 + 77 | Avoid string coercion. | JavaScript |
System.out.println('hello') | System.out.println('hello'); | Add semicolon. | Java |
jwt.sign({{id:25}}, 'token'); | jwt.sign({{id:25}}, 'token', {{expiresIn:'2h'}}); | Add expiration. | Node.js |
function foo(item:string){{return item;}} foo(59); | function foo(item:string){{return item;}} foo('world'); | Pass correct type. | TypeScript |
fn test() -> i32 {{ 22 }} | fn test() -> i32 {{ 22 }} | Correct. | Rust |
<img src='value.jpg'> | <img src='value.jpg' alt='desc'> | Add alt text. | HTML |
values[53] | if (values.indices.contains(53)) values[53] | Check index. | Kotlin |
try {{ throw 'value'; }} catch(e) {{}} | try {{ throw new Error('value'); }} catch(e) {{}} | Throw Error objects. | JavaScript |
String name = 'info'; | String name = 'info'; | Correct. | Dart |
value: value
age: world, | value: value
age: world | Remove comma. | YAML |
disp('hello') | disp('hello') | Correct. | MATLAB |
.Product {{ color: green; }} | .Product {{ color: green; }} | Correct. | CSS |
my @arr = (78,27,30); | my @arr = (78,27,30); | Correct. | Perl |
h1 {{ font-size:49px color:green; }} | h1 {{ font-size:49px; color:green; }} | Add semicolon. | CSS |
// comment | /* comment */ | Use /* */. | CSS |
$result = 44; if ($result = 44) {{}} | $result = 44; if ($result == 44) {{}} | Use ==. | PHP |
cin >> y; | int y;
cin >> y; | Declare variable. | C++ |
<a href='https://example.com' target='_blank'> | <a href='https://example.com' target='_blank' rel='noopener'> | Add rel for security. | HTML |
[65, 2, 3 | [65, 2, 3] | Close bracket. | Ruby |
items.forEach(function(result) {{ console.log(result); }}) | items.forEach((result) => {{ console.log(result); }}) | Arrow functions are cleaner. | JavaScript |
if [ $result = 84 ]; then | if [ "$result" = 84 ]; then | Quote variable. | Shell |
<hr></hr> | <hr> | Self-closing. | HTML |
for (item in arr) | for (item of arr) | for...in iterates keys. | JavaScript |
const item = 14; item = 81; | let item = 14; item = 81; | Cannot reassign const. | JavaScript |
let vec=vec![75,83,85]; let first=&vec[0]; vec.push(32); | let mut vec=vec![75,83,85]; let first=vec[0]; vec.push(32); | Copy instead of reference. | Rust |
for i=1,44 do print(i) end | for i=1,44 do print(i) end | Correct. | Lua |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
<entry name='hello'/> | <entry name="hello"/> | Double quotes. | XML |
class Item {{ int y; }}
obj.y=5; | class Item {{ public int y; }}
obj.y=5; | Make field public. | Java |
if (index = 6) | if (index == 6) | Use ==. | C++ |
var x int | var x int | Correct. | Go |
$arr[79] = 5; | if (isset($arr[79])) $arr[79] = 5; | Check existence. | PHP |
if c = 89: | if c == 89: | Use == for comparison. | Python |
WHERE name = '48' | WHERE name = 48 | Don't quote integer. | SQL |
$data[22] | if ($data.Count -gt 22) {{ $data[22] }} | Check bounds. | PowerShell |
with open('input.csv') as fp:
data = fp.read() | with open('input.csv') as fp:
data = fp.read() | Correct. | Python |
<table><tr><td>world<td>hello</tr></table> | <table><tr><td>world</td><td>hello</td></tr></table> | Close td. | HTML |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
val a: Int = 'hello' | val a: String = 'hello' | Fix type. | Kotlin |
if (x = 84) | if (x == 84) | Use ==. | R |
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(13); | const http = require('http'); http.createServer((req,res) => res.end('result')).listen(13); | Correct. | Node.js |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
[x*x for x in arr if x > 93] | [x*x for x in arr if x > 93] | Correct list comprehension. | Python |
def baz
puts 'hello'
end | def baz
puts 'hello'
end | Correct. | Ruby |
println('message') | println("message") | Double quotes. | Scala |
<p>result <b>test</p></b> | <p>result <b>test</b></p> | Nest properly. | HTML |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
match c {{ 1 => {{}} }} | match c {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
print 'result' | print('result') | print needs parentheses. | Python |
assert num > 69 | assert num > 69 | Correct. | Python |
while index > 51
index -= 1 | while index > 51:
index -= 1 | Colon missing after while. | Python |
if (item = 56) | if (item == 56) | Use ==. | Scala |
val count = 4; count = 10 | var count = 4; count = 10 | Use var for reassignment. | Scala |
const person:Person = {{name:'message'}}; | const person:Person = {{name:'message', age:79}}; | Add missing property. | TypeScript |
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