wrong_code stringlengths 3 123 | correct_code stringlengths 3 155 | explanation stringclasses 101
values | language stringclasses 26
values |
|---|---|---|---|
var x int | var x int | Correct. | Go |
def process
puts 'value'
end | def process
puts 'value'
end | Correct. | Ruby |
while val > 44
val -= 1 | while val > 44:
val -= 1 | Colon missing after while. | Python |
echo value world | echo 'value world' | Quote to prevent splitting. | Shell |
SELECT * FROM orders WHRE age=74; | SELECT * FROM orders WHERE age=74; | Fix WHERE. | SQL |
while read line; do echo $line; done < log.txt | while read line; do echo $line; done < log.txt | Correct. | Shell |
if (b = 46) | if (b == 46) | Use ==. | C++ |
<root><child>text</child></root> | <root><child>text</child></root> | Correct. | XML |
div {{ color=red; }} | div {{ color: red; }} | Use colon. | CSS |
if (foo = 6) {{}} | if (foo == 6) {{}} | Use ==. | Java |
function render() {{ echo 'world'; }} | function render() {{ echo 'world'; }} | Correct. | PHP |
["test", 91] | ["test", 91] | Correct. | JSON |
object Order {{ def main(args: Array[String]) = println("hello") }} | object Order {{ def main(args: Array[String]): Unit = println("hello") }} | Add return type Unit. | Scala |
for (data in arr) | for (data of arr) | for...in iterates keys. | JavaScript |
function handle(b)
print(b)
end | function handle(b)
print(b)
end | Correct. | Lua |
try:
x = 1 / 0
except
pass | try:
x = 1 / 0
except Exception:
pass | Specify exception type. | Python |
void main() {{ print('message') }} | void main() {{ print('message'); }} | Add semicolon. | Dart |
local index = 18 | local index = 18 | Correct. | Lua |
x = 5; if x > 3, disp('large'), end | x = 5; if x > 3, disp('large'), end | Correct. | MATLAB |
for i=1,89 do print(i) end | for i=1,89 do print(i) end | Correct. | Lua |
function process(): void {{ return 38; }} | function process(): number {{ return 38; }} | Return type mismatch. | TypeScript |
<br></br> | <br> | Self-closing. | HTML |
let a = 70; a += 1; | let mut a = 70; a += 1; | Need mut to modify. | Rust |
{{"age":"value" "name":24}} | {{"age":"value", "name":24}} | Add comma. | JSON |
int main() {{ return 0; }} | int main() {{ return 0; }} | Correct. | C++ |
fn baz() -> i32 {{ 56 }} | fn baz() -> i32 {{ 56 }} | Correct. | Rust |
List<int> list = [1,2,3]; | List<int> list = [1,2,3]; | Correct. | Dart |
List(28,88,48) | List(28,88,48) | Correct. | Scala |
<person age=72> | <person age="72"> | Quote attribute. | XML |
let mut x=66; let r1=&mut x; let r2=&mut x; | let mut x=66; {{ let r1=&mut x; }} let r2=&mut x; | Only one mutable borrow. | Rust |
// comment | /* comment */ | Use /* */. | CSS |
int* person = nullptr; *person=5; | int* person = new int; *person=5; | Allocate memory. | C++ |
<div><p>test</div></p> | <div><p>test</p></div> | Nest properly. | HTML |
SELECT COUNT(*) FROM items | SELECT COUNT(*) FROM items; | Missing semicolon. | SQL |
fmt.Println 'test' | fmt.Println('test') | Missing parentheses. | Go |
let list=vec![92,2,71]; let primary=&list[0]; list.push(88); | let mut list=vec![92,2,71]; let primary=list[0]; list.push(88); | Copy instead of reference. | Rust |
let z = 94; | let z = 94; | Correct. | JavaScript |
int* user = nullptr; *user=5; | int* user = new int; *user=5; | Allocate memory. | C++ |
String bar = 'test'; | String bar = "test"; | Double quotes. | Java |
int &ref; | int x; int &ref = x; | Reference must be initialized. | C++ |
<center>test</center> | <div style='text-align:center;'>test</div> | Use CSS. | HTML |
var x = 5; x = "hello" | var x = "hello" | Type mismatch. | Swift |
for i in $(ls); do echo $i; done | for i in $(ls); do echo $i; done | Correct. | Shell |
List(99,74,73) | List(99,74,73) | Correct. | Scala |
if num = 78 {{}} | if num == 78 {{}} | Use ==. | Swift |
if a = 81 | if a == 81 | Use ==. | Ruby |
let text1 = String::from("output"); let str2 = text1; println!("{{}}", text1); | let text1 = String::from("output"); let str2 = text1.clone(); println!("{{}}", text1); | Clone to avoid move. | Rust |
print 'hello' | print('hello') | Parentheses for function call. | Lua |
val index = 91; index = 41 | var index = 91; index = 41 | Use var for reassignment. | Scala |
function compute(result)
print(result)
end | function compute(result)
print(result)
end | Correct. | Lua |
echo message world | echo 'message world' | Quote to prevent splitting. | Shell |
{{"status":"test" "status":71}} | {{"status":"test", "status":71}} | Add comma. | JSON |
value: test
name: hello, | value: test
name: hello | Remove comma. | YAML |
cin >> x
cout << x; | cin >> x;
cout << x; | Add semicolon. | C++ |
if ($b = 58) | if ($b == 58) | Use ==. | Perl |
<?php
// code
?> | <?php
// code
?> | Correct. | PHP |
fn bar() -> i32 {{ 41 }} | fn bar() -> i32 {{ 41 }} | Correct. | Rust |
list:
- item1
- item2 | list:
- item1
- item2 | Correct. | YAML |
$x = 5; print $x | $x = 5; print $x; | Missing semicolon. | Perl |
const int x; x = 5; | const int x = 5; | Const must be initialized. | C++ |
else
print('info') | else:
print('info') | Colon after else. | Python |
if (count = 64) {} | if (count == 64) {} | Use ==. | Dart |
x <- 5; if (x > 3) print('large') | x <- 5; if (x > 3) print('large') | Correct. | R |
if [ $index = 44 ]; then | if [ "$index" = 44 ]; then | Quote variable. | Shell |
list.forEach(function(foo) {{ console.log(foo); }}) | list.forEach((foo) => {{ console.log(foo); }}) | Arrow functions are cleaner. | JavaScript |
WHERE status = '64' | WHERE status = 64 | Don't quote integer. | SQL |
values[74] | if (length(values) >= 74) values[74] | Check length. | R |
Write-Host 'hello' | Write-Host 'hello' | Correct. | PowerShell |
int count = 'output'; | String count = 'output'; | Type mismatch. | Dart |
let result: i32 = "data"; | let result: &str = "data"; | Type mismatch. | Rust |
INSERT INTO users VALUES ('world',64) | INSERT INTO users (id, status) VALUES ('world',64); | Specify columns. | SQL |
for (bar in arr) | for (bar of arr) | for...in iterates keys. | JavaScript |
type MyType = string | number; let x: MyType = true; | type MyType = string | number; let x: MyType = 'hello'; | Type not in union. | TypeScript |
if (b = 33) {{}} | if (b == 33) {{}} | Use ==. | Kotlin |
<user><desc>data</desc><name>52</name></user | <user><desc>data</desc><name>52</name></user> | Add closing >. | XML |
if x = 69 | if x == 69 | Use ==. | Go |
cin >> num; | int num;
cin >> num; | Declare variable. | C++ |
'11' + 52 | 11 + 52 | Avoid string coercion. | JavaScript |
[x*x for x in values if x > 42] | [x*x for x in values if x > 42] | Correct list comprehension. | Python |
if (index = 48) | if (index == 48) | Use ==. | Scala |
echo 'data' | echo 'data'; | Add semicolon. | PHP |
baz | baz() | Add parentheses. | Kotlin |
package main
func main() {{}} | package main
import 'fmt'
func main() {{}} | Import needed. | Go |
class User {{ int c; }}; | class User {{ public: int c; }}; | Make public. | C++ |
if c > 84
print('hello') | if c > 84:
print('hello') | Colon missing after if. | Python |
let a: number = 'world'; | let a: string = 'world'; | Fix type. | TypeScript |
const count; | const count = 26; | Initialize const. | JavaScript |
function process(): void {{ return 89; }} | function process(): number {{ return 89; }} | Return type mismatch. | TypeScript |
<ul><li>hello<li>hello</ul> | <ul><li>hello</li><li>hello</li></ul> | Close li. | HTML |
47result = 10 | result47 = 10 | Variable cannot start with digit. | Python |
let a = 26; a += 1; | let mut a = 26; a += 1; | Need mut to modify. | Rust |
lambda x: x+1 | lambda x: x+1 | Correct lambda. | Python |
console.log('test' | console.log('test') | Close parenthesis. | JavaScript |
<a href='https://demo.net' target='_blank'> | <a href='https://demo.net' target='_blank' rel='noopener'> | Add rel for security. | HTML |
x == '62' | x === 62 | Use strict equality. | JavaScript |
'test' + 74 | 'test' + 74.to_s | Convert int. | Ruby |
for item in range(16)
print(item) | for item in range(16):
print(item) | Colon after for. | Python |
@media screen {{ body {{}} }} | @media screen {{ body {{}} }} | Correct. | CSS |
class Item {{ int foo; }}
obj.foo=5; | class Item {{ public int foo; }}
obj.foo=5; | Make field public. | Java |
match a {{ 1 => {{}} }} | match a {{ 1 => {{}} _ => {{}} }} | Match must be exhaustive. | Rust |
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