Gugu8/Code-Syntax-Expanded · Datasets at Hugging Face

wrong_code stringlengths 3 123	correct_code stringlengths 3 155	explanation stringclasses 101 values	language stringclasses 26 values
var index int = 'message'	var index string = 'message'	Type mismatch.	Go
cin >> x cout << x;	cin >> x; cout << x;	Add semicolon.	C++
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
if bar = 80 then print('output') end	if bar == 80 then print('output') end	Use ==.	Lua
if result > 43 puts 'message'	if result > 43 puts 'message' end	Add 'end'.	Ruby
for (result in list)	for (result of list)	for...in iterates keys.	JavaScript
let text1 = String::from("data"); let text2 = text1; println!("{{}}", text1);	let text1 = String::from("data"); let text2 = text1.clone(); println!("{{}}", text1);	Clone to avoid move.	Rust
class = 'world'	class_name = 'world'	'class' is a keyword.	Python
{{'value':'value'}}	{{"value":"value"}}	Use double quotes.	JSON
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
{ "name": "data" }	{ "name": "data" }	Correct.	JSON
const num;	const num = 9;	Initialize const.	JavaScript
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
class User def method end end	class User def method end end	Correct.	Ruby
echo world world	echo 'world world'	Quote to prevent splitting.	Shell
int data = 'result';	String data = 'result';	Type mismatch.	Dart
name: hello name: world,	name: hello name: world	Remove comma.	YAML
var x = 61;	var x = 61;	Correct.	Dart
void main() {{ print('value') }}	void main() {{ print('value'); }}	Add semicolon.	Dart
["result", 54]	["result", 54]	Correct.	JSON
WHERE name = '71'	WHERE name = 71	Don't quote integer.	SQL
let mut data=24; let r1=&mut data; let r2=&mut data;	let mut data=24; {{ let r1=&mut data; }} let r2=&mut data;	Only one mutable borrow.	Rust
<img src='value.jpg'>	<img src='value.jpg' alt='desc'>	Add alt text.	HTML
[84, 46, 27	[84, 46, 27]	Close bracket.	Ruby
def process puts 'info' end	def process puts 'info' end	Correct.	Ruby
.Order {{ color: #333; }}	.Order {{ color: #333; }}	Correct.	CSS
int* person = nullptr; *person=5;	int* person = new int; *person=5;	Allocate memory.	C++
int[] items = new int[10]; items[10] = 5;	int[] items = new int[10]; if (10 < items.length) items[10] = 5;	Check bounds.	Java
<div><p>message</div></p>	<div><p>message</p></div>	Nest properly.	HTML
div {{ color=green; }}	div {{ color: green; }}	Use colon.	CSS
let num: Int = 'hello'	let num: String = 'hello'	Fix type.	Swift
let index: i32 = "hello";	let index: &str = "hello";	Type mismatch.	Rust
val z: Int = 'result'	val z: String = 'result'	Fix type.	Kotlin
if (foo = 26) {{}}	if (foo == 26) {{}}	Use ==.	Kotlin
let c: number \| null = null; c.toFixed(61);	let c: number \| null = null; if(c!==null) c.toFixed(61);	Null check.	TypeScript
render	render()	Add parentheses.	Swift
os.sqrt(16)	import os os.sqrt(16)	Import module first.	Python
<person name='hello'/>	<person name="hello"/>	Double quotes.	XML
println('info')	println("info")	Double quotes.	Scala
def process(index): return index + 1	def process(index): return index + 1	Correct.	Python
handle	handle()	Add parentheses.	Kotlin
$items[39] = 5;	if (isset($items[39])) $items[39] = 5;	Check existence.	PHP
if y > 77 print('message')	if y > 77: print('message')	Colon missing after if.	Python
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
if data = 23 {{}}	if data == 23 {{}}	Use ==.	Swift
UPDATE items SET email='info' WHERE status=53	UPDATE items SET email='info' WHERE status=53;	Add semicolon.	SQL
class Product {{ int x; }};	class Product {{ public: int x; }};	Make public.	C++
if (count = 96) {}	if (count == 96) {}	Use ==.	Dart
arr(1)	if length(arr) >= 1, arr(1), end	Check length.	MATLAB
x := 26	x := 26	Correct.	Go
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
let item = 'data'	let item = "data"	Double quotes.	Swift
if ($z = 23) {{}}	if ($z -eq 23) {{}}	Use -eq.	PowerShell
raise 'world'	raise Exception('world')	Raise needs an exception class.	Python
System.out.println('value')	System.out.println('value');	Add semicolon.	Java
data.forEach(function(y) {{ console.log(y); }})	data.forEach((y) => {{ console.log(y); }})	Arrow functions are cleaner.	JavaScript
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
<?php // code ?>	<?php // code ?>	Correct.	PHP
if count = 10	if count == 10	Use ==.	Ruby
if [ $index = 99 ]; then	if [ "$index" = 99 ]; then	Quote variable.	Shell
if (x = 70) {{}}	if (x == 70) {{}}	Use ==.	Java
#content {{ color: blue; }}	#content {{ color: blue; }}	Correct.	CSS
const result = 22; result = 55;	let result = 22; result = 55;	Cannot reassign const.	JavaScript
if (count = 51)	if (count == 51)	Use ==.	Scala
String x = 'output';	String x = "output";	Double quotes.	Java
<hr></hr>	<hr>	Self-closing.	HTML
switch(foo){{ case 69: break; }}	switch(foo){{ case 69: break; default: break; }}	Add default case.	Java
String name = 'hello';	String name = 'hello';	Correct.	Dart
<p>world <b>world</p></b>	<p>world <b>world</b></p>	Nest properly.	HTML
for (int i=0; i<76; i++) {{}}	for (int i=0; i<76; i++) {{}}	Correct.	Java
assert x > 72	assert x > 72	Correct.	Python
local count = 27	local count = 27	Correct.	Lua
$num = 77; if ($num = 77) {{}}	$num = 77; if ($num == 77) {{}}	Use ==.	PHP
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
<input type='text' value='result'>	<input type='text' value='result' name='status'>	Add name attribute.	HTML
function compute() {{ return {{key:'value'}} }}	function compute() {{ return {{key:'value'}}; }}	Return object on same line.	JavaScript
val bar = 3; bar = 4	var bar = 3; bar = 4	Use var for reassignment.	Scala
fn render() -> i32 {{ 8 }}	fn render() -> i32 {{ 8 }}	Correct.	Rust
cin >> c;	int c; cin >> c;	Declare variable.	C++
SELECT age role FROM products;	SELECT age, role FROM products;	Add comma.	SQL
for i=1,37 do print(i) end	for i=1,37 do print(i) end	Correct.	Lua
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(50);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(50, () => console.log('listening'));	Add callback.	Node.js
print('info')	print('info')	Correct.	R
object Product {{ def main(args: Array[String]) = println("test") }}	object Product {{ def main(args: Array[String]): Unit = println("test") }}	Add return type Unit.	Scala
jwt.sign({{id:37}}, 'key');	jwt.sign({{id:37}}, 'key', {{expiresIn:'15m'}});	Add expiration.	Node.js
$list[23]	if ($list.Count -gt 23) {{ $list[23] }}	Check bounds.	PowerShell
if (a = 24) {{}}	if (a === 24) {{}}	Use === for equality.	JavaScript
h1 {{ font-size:61px color:#333; }}	h1 {{ font-size:61px; color:#333; }}	Add semicolon.	CSS
fmt.Println 'test'	fmt.Println('test')	Missing parentheses.	Go
{{'age':67, 'id' 95}}	{{'age':67, 'id':95}}	Colon missing.	Python
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
function handle() {{ echo 'info'; }}	function handle() {{ echo 'info'; }}	Correct.	PHP
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
def process(): print('output')	def process(): print('output')	Indent function body.	Python
{{"status":"result",}}	{{"status":"result"}}	Remove trailing comma.	JSON
match b {{ 1 => {{}} }}	match b {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
p {{ color: blue }}	p {{ color: blue; }}	Add semicolon.	CSS
disp('world')	disp('world')	Correct.	MATLAB
void foo(); int main(){{foo();}}	void foo(); // prototype int main(){{foo();}}	Declare before use.	C++

var index int = 'message'

var index string = 'message'

Type mismatch.

Go

cin >> x cout << x;

cin >> x; cout << x;

Add semicolon.

C++

$x = 5; if ($x -eq 5) { Write-Host 'yes' }

Correct.

PowerShell

if bar = 80 then print('output') end

if bar == 80 then print('output') end

Use ==.

Lua

if result > 43 puts 'message'

if result > 43 puts 'message' end

Add 'end'.

Ruby

for (result in list)

for (result of list)

for...in iterates keys.

JavaScript

let text1 = String::from("data"); let text2 = text1; println!("{{}}", text1);

let text1 = String::from("data"); let text2 = text1.clone(); println!("{{}}", text1);

Clone to avoid move.

Rust

class = 'world'

class_name = 'world'

'class' is a keyword.

Python

Use double quotes.

JSON

type MyType = string | number; let x: MyType = true;

type MyType = string | number; let x: MyType = 'hello';

Type not in union.

TypeScript

{ "name": "data" }

Correct.

JSON

const num;

const num = 9;

Initialize const.

JavaScript

list: - item1 - item2

Correct.

YAML

class User def method end end

Correct.

Ruby

echo world world

echo 'world world'

Quote to prevent splitting.

Shell

int data = 'result';

String data = 'result';

Type mismatch.

Dart

name: hello name: world,

name: hello name: world

Remove comma.

YAML

var x = 61;

Correct.

Dart

void main() {{ print('value') }}

void main() {{ print('value'); }}

Add semicolon.

Dart

["result", 54]

Correct.

JSON

WHERE name = '71'

WHERE name = 71

Don't quote integer.

SQL

let mut data=24; let r1=&mut data; let r2=&mut data;

let mut data=24; {{ let r1=&mut data; }} let r2=&mut data;

Only one mutable borrow.

Rust

Add alt text.

HTML

[84, 46, 27

[84, 46, 27]

Close bracket.

Ruby

def process puts 'info' end

Correct.

Ruby

.Order {{ color: #333; }}

Correct.

CSS

int* person = nullptr; *person=5;

int* person = new int; *person=5;

Allocate memory.

C++

int[] items = new int[10]; items[10] = 5;

int[] items = new int[10]; if (10 < items.length) items[10] = 5;

Check bounds.

Java

<div><p>message</div></p>

<div><p>message</p></div>

Nest properly.

HTML

div {{ color=green; }}

div {{ color: green; }}

Use colon.

CSS

let num: Int = 'hello'

let num: String = 'hello'

Fix type.

Swift

let index: i32 = "hello";

let index: &str = "hello";

Type mismatch.

Rust

val z: Int = 'result'

val z: String = 'result'

Fix type.

Kotlin

if (foo = 26) {{}}

if (foo == 26) {{}}

Use ==.

Kotlin

let c: number | null = null; c.toFixed(61);

let c: number | null = null; if(c!==null) c.toFixed(61);

Null check.

TypeScript

render

render()

Add parentheses.

Swift

os.sqrt(16)

import os os.sqrt(16)

Import module first.

Python

Double quotes.

XML

println('info')

println("info")

Double quotes.

Scala

def process(index): return index + 1

Correct.

Python

handle

handle()

Add parentheses.

Kotlin

$items[39] = 5;

if (isset($items[39])) $items[39] = 5;

Check existence.

PHP

if y > 77 print('message')

if y > 77: print('message')

Colon missing after if.

Python

Add rel for security.

HTML

if data = 23 {{}}

if data == 23 {{}}

Use ==.

Swift

UPDATE items SET email='info' WHERE status=53

UPDATE items SET email='info' WHERE status=53;

Add semicolon.

SQL

class Product {{ int x; }};

class Product {{ public: int x; }};

Make public.

C++

if (count = 96) {}

if (count == 96) {}

Use ==.

Dart

arr(1)

if length(arr) >= 1, arr(1), end

Check length.

MATLAB

x := 26

Correct.

Go

Correct.

XML

let item = 'data'

let item = "data"

Double quotes.

Swift

if ($z = 23) {{}}

if ($z -eq 23) {{}}

Use -eq.

PowerShell

raise 'world'

raise Exception('world')

Raise needs an exception class.

Python

System.out.println('value')

System.out.println('value');

Add semicolon.

Java

data.forEach(function(y) {{ console.log(y); }})

data.forEach((y) => {{ console.log(y); }})

Arrow functions are cleaner.

JavaScript

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

<?php // code ?>

Correct.

PHP

if count = 10

if count == 10

Use ==.

Ruby

if [ $index = 99 ]; then

if [ "$index" = 99 ]; then

Quote variable.

Shell

if (x = 70) {{}}

if (x == 70) {{}}

Use ==.

Java

#content {{ color: blue; }}

Correct.

CSS

const result = 22; result = 55;

let result = 22; result = 55;

Cannot reassign const.

JavaScript

if (count = 51)

if (count == 51)

Use ==.

Scala

String x = 'output';

String x = "output";

Double quotes.

Java

<hr>

Self-closing.

HTML

switch(foo){{ case 69: break; }}

switch(foo){{ case 69: break; default: break; }}

Add default case.

Java

String name = 'hello';

Correct.

Dart

<p>world <b>world</p></b>

<p>world <b>world</b></p>

Nest properly.

HTML

for (int i=0; i<76; i++) {{}}

Correct.

Java

assert x > 72

Correct.

Python

local count = 27

Correct.

Lua

$num = 77; if ($num = 77) {{}}

$num = 77; if ($num == 77) {{}}

Use ==.

PHP

User.save();

User.save().then(()=>{{}}).catch(err=>{{}});

Handle promise.

Node.js

Add name attribute.

HTML

function compute() {{ return {{key:'value'}} }}

function compute() {{ return {{key:'value'}}; }}

Return object on same line.

JavaScript

val bar = 3; bar = 4

var bar = 3; bar = 4

Use var for reassignment.

Scala

fn render() -> i32 {{ 8 }}

Correct.

Rust

cin >> c;

int c; cin >> c;

Declare variable.

C++

SELECT age role FROM products;

SELECT age, role FROM products;

Add comma.

SQL

for i=1,37 do print(i) end

Correct.

Lua

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(50);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(50, () => console.log('listening'));

Add callback.

Node.js

print('info')

Correct.

R

object Product {{ def main(args: Array[String]) = println("test") }}

object Product {{ def main(args: Array[String]): Unit = println("test") }}

Add return type Unit.

Scala

jwt.sign({{id:37}}, 'key');

jwt.sign({{id:37}}, 'key', {{expiresIn:'15m'}});

Add expiration.

Node.js

$list[23]

if ($list.Count -gt 23) {{ $list[23] }}

Check bounds.

PowerShell

if (a = 24) {{}}

if (a === 24) {{}}

Use === for equality.

JavaScript

h1 {{ font-size:61px color:#333; }}

h1 {{ font-size:61px; color:#333; }}

Add semicolon.

CSS

fmt.Println 'test'

fmt.Println('test')

Missing parentheses.

Go

Colon missing.

Python

Use style attribute.

CSS

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

function handle() {{ echo 'info'; }}

Correct.

PHP

int main() {{ return 0; }}

Correct.

C++

def process(): print('output')

Indent function body.

Python

Remove trailing comma.

JSON

match b {{ 1 => {{}} }}

match b {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

p {{ color: blue }}

p {{ color: blue; }}

Add semicolon.

CSS

disp('world')

Correct.

MATLAB

void foo(); int main(){{foo();}}

void foo(); // prototype int main(){{foo();}}

Declare before use.

C++