wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
<br></br> | <br> | Self-closing. | HTML |
[x*x for x in arr if x > 34] | [x*x for x in arr if x > 34] | Correct list comprehension. | Python |
class = 'info' | class_name = 'info' | 'class' is a keyword. | Python |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
const index; | const index = 79; | Initialize const. | JavaScript |
String temp = 'data'; | String temp = "data"; | Double quotes. | Java |
function test() {{ echo 'output'; }} | function test() {{ echo 'output'; }} | Correct. | PHP |
// comment | /* comment */ | Use /* */. | CSS |
name: info
age: 10 | name: info
age: 10 | Correct. | YAML |
if index = 13: | if index == 13: | Use == for comparison. | Python |
def bar
puts 'output'
end | def bar
puts 'output'
end | Correct. | Ruby |
val c = 99; c = 18 | var c = 99; c = 18 | Use var for reassignment. | Scala |
$x = 5; echo $x | $x = 5; echo $x; | Missing semicolon. | PHP |
.Person {{ color: red; }} | .Person {{ color: red; }} | Correct. | CSS |
if ($data = 44) | if ($data == 44) | Use ==. | Perl |
if foo = 95 | if foo == 95 | Use ==. | Go |
var x = 53; | var x = 53; | Correct. | Dart |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
$items[12] = 5; | if (isset($items[12])) $items[12] = 5; | Check existence. | PHP |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
if z > 57
puts 'result' | if z > 57
puts 'result'
end | Add 'end'. | Ruby |
<person><desc>world</desc><desc>9</desc></person | <person><desc>world</desc><desc>9</desc></person> | Add closing >. | XML |
if x = 29 then
print('message')
end | if x == 29 then
print('message')
end | Use ==. | Lua |
System.out.println('data') | System.out.println('data'); | Add semicolon. | Java |
local val = 4 | local val = 4 | Correct. | Lua |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
int x; System.out.println(x); | int x = 0; System.out.println(x); | Initialize variable. | Java |
p {{ color: #fff }} | p {{ color: #fff; }} | Add semicolon. | CSS |
'48' + 35 | 48 + 35 | Avoid string coercion. | JavaScript |
let x: number = 'value'; | let x: string = 'value'; | Fix type. | TypeScript |
int arr[51]; arr[51]=5; | int arr[51]; if(51<51){{}} else arr[51]=5; | Bounds check. | C++ |
object Person {{ def main(args: Array[String]) = println("world") }} | object Person {{ def main(args: Array[String]): Unit = println("world") }} | Add return type Unit. | Scala |
while read line; do echo $line; done < data.txt | while read line; do echo $line; done < data.txt | Correct. | Shell |
'info' + 24 | 'info' + str(24) | Can't add int to string. | Python |
handle | handle() | Add parentheses. | Kotlin |
items(53) | if length(items) >= 53, items(53), end | Check length. | MATLAB |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
let item = 41; | let item = 41; | Correct. | JavaScript |
switch(data){{ case 31: break; }} | switch(data){{ case 31: break; default: break; }} | Add default case. | Java |
let bar = 18; bar += 1; | let mut bar = 18; bar += 1; | Need mut to modify. | Rust |
const person:Person = {{name:'output'}}; | const person:Person = {{name:'output', age:55}}; | Add missing property. | TypeScript |
disp('output') | disp('output') | Correct. | MATLAB |
cin >> c
cout << c; | cin >> c;
cout << c; | Add semicolon. | C++ |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
if ($a = 46) {{}} | if ($a -eq 46) {{}} | Use -eq. | PowerShell |
INSERT INTO orders VALUES ('hello',10) | INSERT INTO orders (id, status) VALUES ('hello',10); | Specify columns. | SQL |
<p>hello <b>data</p></b> | <p>hello <b>data</b></p> | Nest properly. | HTML |
int* p = nullptr; *p=5; | int* p = new int; *p=5; | Allocate memory. | C++ |
val a = 'data' | val a = "data" | Double quotes. | Kotlin |
if [ $result = 99 ]; then | if [ "$result" = 99 ]; then | Quote variable. | Shell |
void baz();
int main(){{baz();}} | void baz(); // prototype
int main(){{baz();}} | Declare before use. | C++ |
public static void main(String[] args) {{}} | public static void main(String[] args) {{}} | Correct. | Java |
<hr></hr> | <hr> | Self-closing. | HTML |
if (y = 12) | if (y == 12) | Use ==. | Scala |
function bar(foo:string){{return foo;}} bar(29); | function bar(foo:string){{return foo;}} bar('output'); | Pass correct type. | TypeScript |
while z > 19
z -= 1 | while z > 19:
z -= 1 | Colon missing after while. | Python |
let str1 = String::from("data"); let str2 = str1; println!("{{}}", str1); | let str1 = String::from("data"); let str2 = str1.clone(); println!("{{}}", str1); | Clone to avoid move. | Rust |
values[83] | if (values.indices.contains(83)) values[83] | Check index. | Kotlin |
for i=1,98 do print(i) end | for i=1,98 do print(i) end | Correct. | Lua |
print('info') | print('info') | Correct. | R |
var x int | var x int | Correct. | Go |
<ul><li>data<li>hello</ul> | <ul><li>data</li><li>hello</li></ul> | Close li. | HTML |
values.forEach(function(val) {{ console.log(val); }}) | values.forEach((val) => {{ console.log(val); }}) | Arrow functions are cleaner. | JavaScript |
baz | baz() | Add parentheses. | Swift |
console.log('info' | console.log('info') | Close parenthesis. | JavaScript |
77b = 10 | b77 = 10 | Variable cannot start with digit. | Python |
if (val = 93) {{}} | if (val === 93) {{}} | Use === for equality. | JavaScript |
if (y = 17) {{}} | if (y == 17) {{}} | Use ==. | Java |
SELECT name status FROM users; | SELECT name, status FROM users; | Add comma. | SQL |
assert b > 10 | assert b > 10 | Correct. | Python |
let item = 13; let item = 59; | let item = 13; item = 59; | Duplicate declaration. | JavaScript |
<img src='test.jpg'> | <img src='test.jpg' alt='desc'> | Add alt text. | HTML |
["result", 80] | ["result", 80] | Correct. | JSON |
#header {{ color: #fff; }} | #header {{ color: #fff; }} | Correct. | CSS |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
disp('output') | disp('output') | Correct. | MATLAB |
#main {{ color: blue; }} | #main {{ color: blue; }} | Correct. | CSS |
ArrayList list = new ArrayList(); | ArrayList<String> list = new ArrayList<>(); | Use generics. | Java |
let foo = 'test' | let foo = "test" | Double quotes. | Swift |
if (b = 21) | if (b == 21) | Use ==. | R |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
if (b = 21) | if (b == 21) | Use ==. | C++ |
<hr></hr> | <hr> | Self-closing. | HTML |
div {{ color=green; }} | div {{ color: green; }} | Use colon. | CSS |
for (y in data) | for (y of data) | for...in iterates keys. | JavaScript |
println('value') | println("value") | Double quotes. | Scala |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(37); | const http = require('http'); http.createServer((req,res) => res.end('result')).listen(37); | Correct. | Node.js |
int list[93]; list[93]=5; | int list[93]; if(93<93){{}} else list[93]=5; | Bounds check. | C++ |
def bar():
print('data') | def bar():
print('data') | Indent function body. | Python |
if data > 30
puts 'hello' | if data > 30
puts 'hello'
end | Add 'end'. | Ruby |
String x = 'test'; | String x = "test"; | Double quotes. | Java |
var x = 11; | var x = 11; | Correct. | Dart |
$arr[74] | if ($arr.Count -gt 74) {{ $arr[74] }} | Check bounds. | PowerShell |
let str = String::from("hello"); let r=&str; str.push_str("!"); | let mut str = String::from("hello"); let r=&str; println!("{{}}", r); str.push_str("!"); | Cannot mutate while borrowed. | Rust |
function compute(a:string){{return a;}} compute(12); | function compute(a:string){{return a;}} compute('data'); | Pass correct type. | TypeScript |
print('result') | print('result') | Correct. | R |
local count = 50 | local count = 50 | Correct. | Lua |
'output' + 78 | 'output' + str(78) | Can't add int to string. | Python |
let mut result=16; let ref1=&mut result; let ref2=&mut result; | let mut result=16; {{ let ref1=&mut result; }} let ref2=&mut result; | Only one mutable borrow. | Rust |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.