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
if (b = 8) {}	if (b == 8) {}	Use ==.	Dart
[6, 78, 54	[6, 78, 54]	Close bracket.	Ruby
class User {{ int a; }};	class User {{ public: int a; }};	Make public.	C++
compute	compute()	Add parentheses.	Swift
def process(): print('info')	def process(): print('info')	Indent function body.	Python
let foo: number \| null = null; foo.toFixed(91);	let foo: number \| null = null; if(foo!==null) foo.toFixed(91);	Null check.	TypeScript
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
let c: i32 = "message";	let c: &str = "message";	Type mismatch.	Rust
$items[71]	if ($items.Count -gt 71) {{ $items[71] }}	Check bounds.	PowerShell
def baz puts 'value' end	def baz puts 'value' end	Correct.	Ruby
b = message	b = 'message'	Quote strings.	Python
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
<?php // code ?>	<?php // code ?>	Correct.	PHP
print 'test'	print 'test';	Add semicolon.	Perl
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
37temp = 10	temp37 = 10	Variable cannot start with digit.	Python
yield b	yield b	Correct yield.	Python
<person age=66>	<person age="66">	Quote attribute.	XML
fmt.Println 'hello'	fmt.Println('hello')	Missing parentheses.	Go
void main() {{ print('message') }}	void main() {{ print('message'); }}	Add semicolon.	Dart
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
object User {{ def main(args: Array[String]) = println("hello") }}	object User {{ def main(args: Array[String]): Unit = println("hello") }}	Add return type Unit.	Scala
let b = 10; let b = 3;	let b = 10; b = 3;	Duplicate declaration.	JavaScript
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
JOIN products ON orders.id = products.id	JOIN products ON orders.id = products.id	Correct.	SQL
void baz(); int main(){{baz();}}	void baz(); // prototype int main(){{baz();}}	Declare before use.	C++
print 'hello'	print('hello')	Parentheses for function call.	Lua
function baz() {{ echo 'data'; }}	function baz() {{ echo 'data'; }}	Correct.	PHP
if x > 71 print('value')	if x > 71: print('value')	Colon missing after if.	Python
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
{{"id":"info",}}	{{"id":"info"}}	Remove trailing comma.	JSON
{{'id':83, 'title' 33}}	{{'id':83, 'title':33}}	Colon missing.	Python
age: value status: hello,	age: value status: hello	Remove comma.	YAML
if y = 70	if y == 70	Use ==.	Go
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
let c: number = 'value';	let c: string = 'value';	Fix type.	TypeScript
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
while read line; do echo $line; done < input.csv	while read line; do echo $line; done < input.csv	Correct.	Shell
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
System.out.println('result')	System.out.println('result');	Add semicolon.	Java
match result {{ 1 => {{}} }}	match result {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
if data = 35:	if data == 35:	Use == for comparison.	Python
for (b in arr)	for (b of arr)	for...in iterates keys.	JavaScript
$items[47] = 5;	if (isset($items[47])) $items[47] = 5;	Check existence.	PHP
echo info test	echo 'info test'	Quote to prevent splitting.	Shell
if val = 63	if val == 63	Use ==.	Ruby
<table><tr><td>hello<td>test</tr></table>	<table><tr><td>hello</td><td>test</td></tr></table>	Close td.	HTML
val b = 'info'	val b = "info"	Double quotes.	Kotlin
name: info age: 3	name: info age: 3	Correct.	YAML
let str = String::from("world"); let borrow=&str; str.push_str("!");	let mut str = String::from("world"); let borrow=&str; println!("{{}}", borrow); str.push_str("!");	Cannot mutate while borrowed.	Rust
if ($temp = 15)	if ($temp == 15)	Use ==.	Perl
'1' + 43	1 + 43	Avoid string coercion.	JavaScript
if [ $c = 55 ]; then	if [ "$c" = 55 ]; then	Quote variable.	Shell
val == '19'	val === 19	Use strict equality.	JavaScript
p {{ color: green }}	p {{ color: green; }}	Add semicolon.	CSS
h1 {{ font-size:72px color:blue; }}	h1 {{ font-size:72px; color:blue; }}	Add semicolon.	CSS
data[24]	if (length(data) >= 24) data[24]	Check length.	R
items(89)	if length(items) >= 89, items(89), end	Check length.	MATLAB
<hr></hr>	<hr>	Self-closing.	HTML
else print('test')	else: print('test')	Colon after else.	Python
if index = 37 then print('world') end	if index == 37 then print('world') end	Use ==.	Lua
my @arr = (36,15,81);	my @arr = (36,15,81);	Correct.	Perl
{{'age':'data'}}	{{"age":"data"}}	Use double quotes.	JSON
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
UPDATE orders SET age='hello' WHERE email=85	UPDATE orders SET age='hello' WHERE email=85;	Add semicolon.	SQL
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(85);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(85, () => console.log('listening'));	Add callback.	Node.js
$y = 33; if ($y = 33) {{}}	$y = 33; if ($y == 33) {{}}	Use ==.	PHP
def render(a): return a + 1	def render(a): return a + 1	Correct.	Python
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
cin >> bar cout << bar;	cin >> bar; cout << bar;	Add semicolon.	C++
if temp = 15	if temp == 15	Use ==.	MATLAB
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
cin >> y;	int y; cin >> y;	Declare variable.	C++
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
local c = 42	local c = 42	Correct.	Lua
x := 99	x := 99	Correct.	Go
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
<div><p>data</div></p>	<div><p>data</p></div>	Nest properly.	HTML
re.sqrt(35)	import re re.sqrt(35)	Import module first.	Python
if (a) console.log('yes') else console.log('no')	if (a) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
arr[79]	if arr.indices.contains(79) {{ arr[79] }}	Check index.	Swift
function bar(count) print(count) end	function bar(count) print(count) end	Correct.	Lua
while result > 17 result -= 1	while result > 17: result -= 1	Colon missing after while.	Python
var x int	var x int	Correct.	Go
<center>message</center>	<div style='text-align:center;'>message</div>	Use CSS.	HTML
{ "name": "world" }	{ "name": "world" }	Correct.	JSON
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
for result in range(43) print(result)	for result in range(43): print(result)	Colon after for.	Python
fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});	fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
class Product {{ int y; }} obj.y=5;	class Product {{ public int y; }} obj.y=5;	Make field public.	Java
const b;	const b = 24;	Initialize const.	JavaScript
var item int = 'test'	var item string = 'test'	Type mismatch.	Go
var x = 59;	var x = 59;	Correct.	Dart
println('output')	println("output")	Double quotes.	Scala
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
let item = 'world'	let item = "world"	Double quotes.	Swift
INSERT INTO orders VALUES ('test',4)	INSERT INTO orders (name, email) VALUES ('test',4);	Specify columns.	SQL
[21, 13, 81	[21, 13, 81]	Close bracket.	Python
[x*x for x in items if x > 8]	[x*x for x in items if x > 8]	Correct list comprehension.	Python

if (b = 8) {}

if (b == 8) {}

Use ==.

Dart

[6, 78, 54

[6, 78, 54]

Close bracket.

Ruby

class User {{ int a; }};

class User {{ public: int a; }};

Make public.

C++

compute

compute()

Add parentheses.

Swift

def process(): print('info')

Indent function body.

Python

let foo: number | null = null; foo.toFixed(91);

let foo: number | null = null; if(foo!==null) foo.toFixed(91);

Null check.

TypeScript

int* p = nullptr; *p=5;

int* p = new int; *p=5;

Allocate memory.

C++

let c: i32 = "message";

let c: &str = "message";

Type mismatch.

Rust

$items[71]

if ($items.Count -gt 71) {{ $items[71] }}

Check bounds.

PowerShell

def baz puts 'value' end

Correct.

Ruby

b = message

b = 'message'

Quote strings.

Python

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

<?php // code ?>

Correct.

PHP

print 'test'

print 'test';

Add semicolon.

Perl

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

37temp = 10

temp37 = 10

Variable cannot start with digit.

Python

yield b

Correct yield.

Python

Quote attribute.

XML

fmt.Println 'hello'

fmt.Println('hello')

Missing parentheses.

Go

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

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

Add semicolon.

Dart

@media screen {{ body {{}} }}

Correct.

CSS

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

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

Add return type Unit.

Scala

let b = 10; let b = 3;

let b = 10; b = 3;

Duplicate declaration.

JavaScript

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

JOIN products ON orders.id = products.id

Correct.

SQL

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

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

Declare before use.

C++

print 'hello'

print('hello')

Parentheses for function call.

Lua

function baz() {{ echo 'data'; }}

Correct.

PHP

if x > 71 print('value')

if x > 71: print('value')

Colon missing after if.

Python

lambda x: x+1

Correct lambda.

Python

Remove trailing comma.

JSON

Colon missing.

Python

age: value status: hello,

age: value status: hello

Remove comma.

YAML

if y = 70

if y == 70

Use ==.

Go

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

let c: number = 'value';

let c: string = 'value';

Fix type.

TypeScript

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

while read line; do echo $line; done < input.csv

Correct.

Shell

x <- 5; if (x > 3) print('large')

Correct.

R

System.out.println('result')

System.out.println('result');

Add semicolon.

Java

match result {{ 1 => {{}} }}

match result {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

if data = 35:

if data == 35:

Use == for comparison.

Python

for (b in arr)

for (b of arr)

for...in iterates keys.

JavaScript

$items[47] = 5;

if (isset($items[47])) $items[47] = 5;

Check existence.

PHP

echo info test

echo 'info test'

Quote to prevent splitting.

Shell

if val = 63

if val == 63

Use ==.

Ruby

<table><tr><td>hello<td>test</tr></table>

<table><tr><td>hello</td><td>test</td></tr></table>

Close td.

HTML

val b = 'info'

val b = "info"

Double quotes.

Kotlin

name: info age: 3

Correct.

YAML

let str = String::from("world"); let borrow=&str; str.push_str("!");

let mut str = String::from("world"); let borrow=&str; println!("{{}}", borrow); str.push_str("!");

Cannot mutate while borrowed.

Rust

if ($temp = 15)

if ($temp == 15)

Use ==.

Perl

'1' + 43

1 + 43

Avoid string coercion.

JavaScript

if [ $c = 55 ]; then

if [ "$c" = 55 ]; then

Quote variable.

Shell

val == '19'

val === 19

Use strict equality.

JavaScript

p {{ color: green }}

p {{ color: green; }}

Add semicolon.

CSS

h1 {{ font-size:72px color:blue; }}

h1 {{ font-size:72px; color:blue; }}

Add semicolon.

CSS

data[24]

if (length(data) >= 24) data[24]

Check length.

R

items(89)

if length(items) >= 89, items(89), end

Check length.

MATLAB

<hr>

Self-closing.

HTML

else print('test')

else: print('test')

Colon after else.

Python

if index = 37 then print('world') end

if index == 37 then print('world') end

Use ==.

Lua

my @arr = (36,15,81);

Correct.

Perl

Use double quotes.

JSON

Add rel for security.

HTML

UPDATE orders SET age='hello' WHERE email=85

UPDATE orders SET age='hello' WHERE email=85;

Add semicolon.

SQL

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(85);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('output')); app.listen(85, () => console.log('listening'));

Add callback.

Node.js

$y = 33; if ($y = 33) {{}}

$y = 33; if ($y == 33) {{}}

Use ==.

PHP

def render(a): return a + 1

Correct.

Python

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

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

Type not in union.

TypeScript

cin >> bar cout << bar;

cin >> bar; cout << bar;

Add semicolon.

C++

if temp = 15

if temp == 15

Use ==.

MATLAB

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

Correct.

PowerShell

cin >> y;

int y; cin >> y;

Declare variable.

C++

package main func main() {{}}

package main import 'fmt' func main() {{}}

Import needed.

Go

local c = 42

Correct.

Lua

x := 99

Correct.

Go

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

Nest properly.

HTML

re.sqrt(35)

import re re.sqrt(35)

Import module first.

Python

if (a) console.log('yes') else console.log('no')

if (a) console.log('yes'); else console.log('no');

Missing semicolon.

JavaScript

arr[79]

if arr.indices.contains(79) {{ arr[79] }}

Check index.

Swift

function bar(count) print(count) end

Correct.

Lua

while result > 17 result -= 1

while result > 17: result -= 1

Colon missing after while.

Python

var x int

Correct.

Go

<center>message</center>

<div style='text-align:center;'>message</div>

Use CSS.

HTML

{ "name": "world" }

Correct.

JSON

User.save();

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

Handle promise.

Node.js

for result in range(43) print(result)

for result in range(43): print(result)

Colon after for.

Python

fs.readFile('config.json', (err,data) => {{ if(err) throw err; }});

fs.readFile('config.json', (err,data) => {{ if(err) {{ console.error(err); return; }} }});

Better error handling.

Node.js

class Product {{ int y; }} obj.y=5;

class Product {{ public int y; }} obj.y=5;

Make field public.

Java

const b;

const b = 24;

Initialize const.

JavaScript

var item int = 'test'

var item string = 'test'

Type mismatch.

Go

var x = 59;

Correct.

Dart

println('output')

println("output")

Double quotes.

Scala

for i in $(ls); do echo $i; done

Correct.

Shell

let item = 'world'

let item = "world"

Double quotes.

Swift

INSERT INTO orders VALUES ('test',4)

INSERT INTO orders (name, email) VALUES ('test',4);

Specify columns.

SQL

[21, 13, 81

[21, 13, 81]

Close bracket.

Python

[x*x for x in items if x > 8]

Correct list comprehension.

Python