Gugu8/Code-Syntax · Datasets at Hugging Face

wrong_code stringlengths 3 123	correct_code stringlengths 3 155	explanation stringclasses 83 values	language stringclasses 23 values
["value", 99]	["value", 99]	Correct.	JSON
if (foo = 45) {{}}	if (foo === 45) {{}}	Use === for equality.	JavaScript
$data[33] = 5;	if (isset($data[33])) $data[33] = 5;	Check existence.	PHP
String c = 'output';	String c = "output";	Double quotes.	Java
jwt.sign({{id:44}}, 'token');	jwt.sign({{id:44}}, 'token', {{expiresIn:'2h'}});	Add expiration.	Node.js
// comment	/* comment */	Use /* */.	CSS
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
if [ $result = 42 ]; then	if [ "$result" = 42 ]; then	Quote variable.	Shell
print 'value'	print('value')	print needs parentheses.	Python
with open('data.txt') as fp: data = fp.read()	with open('data.txt') as fp: data = fp.read()	Correct.	Python
h1 {{ font-size:1px color:green; }}	h1 {{ font-size:1px; color:green; }}	Add semicolon.	CSS
SELECT name role FROM orders;	SELECT name, role FROM orders;	Add comma.	SQL
<hr></hr>	<hr>	Self-closing.	HTML
c == '25'	c === 25	Use strict equality.	JavaScript
print('result')	print('result')	Correct.	R
function foo(x:string){{return x;}} foo(20);	function foo(x:string){{return x;}} foo('result');	Pass correct type.	TypeScript
Write-Host 'info'	Write-Host 'info'	Correct.	PowerShell
def bar puts 'test' end	def bar puts 'test' end	Correct.	Ruby
DELETE FROM orders WHERE age=93	DELETE FROM orders WHERE age=93;	Add semicolon.	SQL
test	test()	Add parentheses.	Swift
let text = String::from("result"); let r=&text; text.push_str("!");	let mut text = String::from("result"); let r=&text; println!("{{}}", r); text.push_str("!");	Cannot mutate while borrowed.	Rust
let c: i32 = "test";	let c: &str = "test";	Type mismatch.	Rust
96num = 10	num96 = 10	Variable cannot start with digit.	Python
class = 'value'	class_name = 'value'	'class' is a keyword.	Python
def compute(item): return item + 1	def compute(item): return item + 1	Correct.	Python
if ($x = 88)	if ($x == 88)	Use ==.	Perl
my @arr = (74,67,96);	my @arr = (74,67,96);	Correct.	Perl
UPDATE items SET age='message' WHERE role=78	UPDATE items SET age='message' WHERE role=78;	Add semicolon.	SQL
for num in range(55) print(num)	for num in range(55): print(num)	Colon after for.	Python
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
assert z > 45	assert z > 45	Correct.	Python
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
INSERT INTO products VALUES ('test',100)	INSERT INTO products (name, email) VALUES ('test',100);	Specify columns.	SQL
items.forEach(function(z) {{ console.log(z); }})	items.forEach((z) => {{ console.log(z); }})	Arrow functions are cleaner.	JavaScript
math.sqrt(94)	import math math.sqrt(94)	Import module first.	Python
if num = 94	if num == 94	Use ==.	Ruby
'output' + 27	'output' + 27.to_s	Convert int.	Ruby
echo value data	echo 'value data'	Quote to prevent splitting.	Shell
let data = 'data'	let data = "data"	Double quotes.	Swift
val = 26	val=26	No spaces.	Shell
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(88);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(88, () => console.log('listening'));	Add callback.	Node.js
if c = 55:	if c == 55:	Use == for comparison.	Python
match temp {{ 1 => {{}} }}	match temp {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
function handle() {{ return {{key:'world'}} }}	function handle() {{ return {{key:'world'}}; }}	Return object on same line.	JavaScript
#content {{ color: #333; }}	#content {{ color: #333; }}	Correct.	CSS
{{'name':'test'}}	{{"name":"test"}}	Use double quotes.	JSON
if (count = 41)	if (count == 41)	Use ==.	C++
raise 'world'	raise Exception('world')	Raise needs an exception class.	Python
let list=vec![59,71,50]; let head=&list[0]; list.push(65);	let mut list=vec![59,71,50]; let head=list[0]; list.push(65);	Copy instead of reference.	Rust
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
class Order {{ int num; }} obj.num=5;	class Order {{ public int num; }} obj.num=5;	Make field public.	Java
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
if (foo = 26) {{}}	if (foo == 26) {{}}	Use ==.	Java
function compute(): void {{ return 71; }}	function compute(): number {{ return 71; }}	Return type mismatch.	TypeScript
'2' + 66	2 + 66	Avoid string coercion.	JavaScript
fn test() -> i32 {{ 2 }}	fn test() -> i32 {{ 2 }}	Correct.	Rust
else print('message')	else: print('message')	Colon after else.	Python
p {{ color: red }}	p {{ color: red; }}	Add semicolon.	CSS
fmt.Println 'data'	fmt.Println('data')	Missing parentheses.	Go
items[66]	if (length(items) >= 66) items[66]	Check length.	R
let foo: number \| null = null; foo.toFixed(100);	let foo: number \| null = null; if(foo!==null) foo.toFixed(100);	Null check.	TypeScript
.Item {{ color: blue; }}	.Item {{ color: blue; }}	Correct.	CSS
let z: number = 'data';	let z: string = 'data';	Fix type.	TypeScript
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
let num = 23;	let num = 23;	Correct.	JavaScript
items[47]	if (items.indices.contains(47)) items[47]	Check index.	Kotlin
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
const result;	const result = 10;	Initialize const.	JavaScript
<p>value <b>test</p></b>	<p>value <b>test</b></p>	Nest properly.	HTML
<img src='value.jpg'>	<img src='value.jpg' alt='desc'>	Add alt text.	HTML
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
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
function render() {{ echo 'world'; }}	function render() {{ echo 'world'; }}	Correct.	PHP
if item > 2 puts 'output'	if item > 2 puts 'output' end	Add 'end'.	Ruby
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
let s1 = String::from("result"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("result"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
print 'data'	print 'data';	Add semicolon.	Perl
id: info age: test,	id: info age: test	Remove comma.	YAML
if (data = 48) {{}}	if (data == 48) {{}}	Use ==.	Kotlin
$x = 61; if ($x = 61) {{}}	$x = 61; if ($x == 61) {{}}	Use ==.	PHP
[85, 83, 67	[85, 83, 67]	Close bracket.	Python
cin >> data;	int data; cin >> data;	Declare variable.	C++
try {{ throw 'result'; }} catch(e) {{}}	try {{ throw new Error('result'); }} catch(e) {{}}	Throw Error objects.	JavaScript
process	process()	Add parentheses.	Kotlin
Post.save();	Post.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
<center>result</center>	<div style='text-align:center;'>result</div>	Use CSS.	HTML
WHERE status = '4'	WHERE status = 4	Don't quote integer.	SQL
<div color=blue>	<div style='color:blue;'>	Use style attribute.	CSS
items[94]	if items.indices.contains(94) {{ items[94] }}	Check index.	Swift
y > 70 & y < 66	y > 70 and y < 66	Use 'and' not '&'.	Python
if ($a = 59) {{}}	if ($a -eq 59) {{}}	Use -eq.	PowerShell
{{"age":"result",}}	{{"age":"result"}}	Remove trailing comma.	JSON
<?php // code ?>	<?php // code ?>	Correct.	PHP
cin >> b cout << b;	cin >> b; cout << b;	Add semicolon.	C++
<br></br>	<br>	Self-closing.	HTML
for (foo in data)	for (foo of data)	for...in iterates keys.	JavaScript
x := 53	x := 53	Correct.	Go
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
{{'id':71, 'id' 78}}	{{'id':71, 'id':78}}	Colon missing.	Python
disp('value')	disp('value')	Correct.	MATLAB

["value", 99]

Correct.

JSON

if (foo = 45) {{}}

if (foo === 45) {{}}

Use === for equality.

JavaScript

$data[33] = 5;

if (isset($data[33])) $data[33] = 5;

Check existence.

PHP

String c = 'output';

String c = "output";

Double quotes.

Java

jwt.sign({{id:44}}, 'token');

jwt.sign({{id:44}}, 'token', {{expiresIn:'2h'}});

Add expiration.

Node.js

// comment

/* comment */

Use /* */.

CSS

Add rel for security.

HTML

if [ $result = 42 ]; then

if [ "$result" = 42 ]; then

Quote variable.

Shell

print 'value'

print('value')

print needs parentheses.

Python

with open('data.txt') as fp: data = fp.read()

Correct.

Python

h1 {{ font-size:1px color:green; }}

h1 {{ font-size:1px; color:green; }}

Add semicolon.

CSS

SELECT name role FROM orders;

SELECT name, role FROM orders;

Add comma.

SQL

<hr>

Self-closing.

HTML

c == '25'

c === 25

Use strict equality.

JavaScript

print('result')

Correct.

R

function foo(x:string){{return x;}} foo(20);

function foo(x:string){{return x;}} foo('result');

Pass correct type.

TypeScript

Write-Host 'info'

Correct.

PowerShell

def bar puts 'test' end

Correct.

Ruby

DELETE FROM orders WHERE age=93

DELETE FROM orders WHERE age=93;

Add semicolon.

SQL

test

test()

Add parentheses.

Swift

let text = String::from("result"); let r=&text; text.push_str("!");

let mut text = String::from("result"); let r=&text; println!("{{}}", r); text.push_str("!");

Cannot mutate while borrowed.

Rust

let c: i32 = "test";

let c: &str = "test";

Type mismatch.

Rust

96num = 10

num96 = 10

Variable cannot start with digit.

Python

class = 'value'

class_name = 'value'

'class' is a keyword.

Python

def compute(item): return item + 1

Correct.

Python

if ($x = 88)

if ($x == 88)

Use ==.

Perl

my @arr = (74,67,96);

Correct.

Perl

UPDATE items SET age='message' WHERE role=78

UPDATE items SET age='message' WHERE role=78;

Add semicolon.

SQL

for num in range(55) print(num)

for num in range(55): print(num)

Colon after for.

Python

list: - item1 - item2

Correct.

YAML

assert z > 45

Correct.

Python

ArrayList list = new ArrayList();

ArrayList<String> list = new ArrayList<>();

Use generics.

Java

INSERT INTO products VALUES ('test',100)

INSERT INTO products (name, email) VALUES ('test',100);

Specify columns.

SQL

items.forEach(function(z) {{ console.log(z); }})

items.forEach((z) => {{ console.log(z); }})

Arrow functions are cleaner.

JavaScript

math.sqrt(94)

import math math.sqrt(94)

Import module first.

Python

if num = 94

if num == 94

Use ==.

Ruby

'output' + 27

'output' + 27.to_s

Convert int.

Ruby

echo value data

echo 'value data'

Quote to prevent splitting.

Shell

let data = 'data'

let data = "data"

Double quotes.

Swift

val = 26

val=26

No spaces.

Shell

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(88);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(88, () => console.log('listening'));

Add callback.

Node.js

if c = 55:

if c == 55:

Use == for comparison.

Python

match temp {{ 1 => {{}} }}

match temp {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

function handle() {{ return {{key:'world'}} }}

function handle() {{ return {{key:'world'}}; }}

Return object on same line.

JavaScript

#content {{ color: #333; }}

Correct.

CSS

Use double quotes.

JSON

if (count = 41)

if (count == 41)

Use ==.

C++

raise 'world'

raise Exception('world')

Raise needs an exception class.

Python

let list=vec![59,71,50]; let head=&list[0]; list.push(65);

let mut list=vec![59,71,50]; let head=list[0]; list.push(65);

Copy instead of reference.

Rust

package main func main() {{}}

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

Import needed.

Go

class Order {{ int num; }} obj.num=5;

class Order {{ public int num; }} obj.num=5;

Make field public.

Java

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

if (foo = 26) {{}}

if (foo == 26) {{}}

Use ==.

Java

function compute(): void {{ return 71; }}

function compute(): number {{ return 71; }}

Return type mismatch.

TypeScript

'2' + 66

2 + 66

Avoid string coercion.

JavaScript

fn test() -> i32 {{ 2 }}

Correct.

Rust

else print('message')

else: print('message')

Colon after else.

Python

p {{ color: red }}

p {{ color: red; }}

Add semicolon.

CSS

fmt.Println 'data'

fmt.Println('data')

Missing parentheses.

Go

items[66]

if (length(items) >= 66) items[66]

Check length.

R

let foo: number | null = null; foo.toFixed(100);

let foo: number | null = null; if(foo!==null) foo.toFixed(100);

Null check.

TypeScript

.Item {{ color: blue; }}

Correct.

CSS

let z: number = 'data';

let z: string = 'data';

Fix type.

TypeScript

int* p = nullptr; *p=5;

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

Allocate memory.

C++

let num = 23;

Correct.

JavaScript

items[47]

if (items.indices.contains(47)) items[47]

Check index.

Kotlin

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

Correct.

Shell

const result;

const result = 10;

Initialize const.

JavaScript

<p>value <b>test</p></b>

<p>value <b>test</b></p>

Nest properly.

HTML

Add alt text.

HTML

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

Correct.

XML

function render() {{ echo 'world'; }}

Correct.

PHP

if item > 2 puts 'output'

if item > 2 puts 'output' end

Add 'end'.

Ruby

public static void main(String[] args) {{}}

Correct.

Java

let s1 = String::from("result"); let str2 = s1; println!("{{}}", s1);

let s1 = String::from("result"); let str2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

print 'data'

print 'data';

Add semicolon.

Perl

id: info age: test,

id: info age: test

Remove comma.

YAML

if (data = 48) {{}}

if (data == 48) {{}}

Use ==.

Kotlin

$x = 61; if ($x = 61) {{}}

$x = 61; if ($x == 61) {{}}

Use ==.

PHP

[85, 83, 67

[85, 83, 67]

Close bracket.

Python

cin >> data;

int data; cin >> data;

Declare variable.

C++

try {{ throw 'result'; }} catch(e) {{}}

try {{ throw new Error('result'); }} catch(e) {{}}

Throw Error objects.

JavaScript

process

process()

Add parentheses.

Kotlin

Post.save();

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

Handle promise.

Node.js

<center>result</center>

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

Use CSS.

HTML

WHERE status = '4'

WHERE status = 4

Don't quote integer.

SQL

Use style attribute.

CSS

items[94]

if items.indices.contains(94) {{ items[94] }}

Check index.

Swift

y > 70 & y < 66

y > 70 and y < 66

Use 'and' not '&'.

Python

if ($a = 59) {{}}

if ($a -eq 59) {{}}

Use -eq.

PowerShell

Remove trailing comma.

JSON

<?php // code ?>

Correct.

PHP

cin >> b cout << b;

cin >> b; cout << b;

Add semicolon.

C++

<br>

Self-closing.

HTML

for (foo in data)

for (foo of data)

for...in iterates keys.

JavaScript

x := 53

Correct.

Go

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

Colon missing.

Python

disp('value')

Correct.

MATLAB