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 (item) console.log('yes') else console.log('no')	if (item) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
String val = 'info';	String val = "info";	Double quotes.	Java
local x = 42	local x = 42	Correct.	Lua
val item: Int = 'result'	val item: String = 'result'	Fix type.	Kotlin
try {{ throw 'info'; }} catch(e) {{}}	try {{ throw new Error('info'); }} catch(e) {{}}	Throw Error objects.	JavaScript
for (int i=0; i<30; i++) {{}}	for (int i=0; i<30; i++) {{}}	Correct.	Java
if ($bar = 23) {{}}	if ($bar -eq 23) {{}}	Use -eq.	PowerShell
<ul><li>test<li>world</ul>	<ul><li>test</li><li>world</li></ul>	Close li.	HTML
[x*x for x in arr if x > 73]	[x*x for x in arr if x > 73]	Correct list comprehension.	Python
if b > 66 puts 'world'	if b > 66 puts 'world' end	Add 'end'.	Ruby
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
fn compute() -> i32 {{ 43 }}	fn compute() -> i32 {{ 43 }}	Correct.	Rust
class User {{ int a; }} obj.a=5;	class User {{ public int a; }} obj.a=5;	Make field public.	Java
os.sqrt(66)	import os os.sqrt(66)	Import module first.	Python
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
if index = 95 {{}}	if index == 95 {{}}	Use ==.	Swift
jwt.sign({{id:70}}, 'password');	jwt.sign({{id:70}}, 'password', {{expiresIn:'1h'}});	Add expiration.	Node.js
const z = 88; z = 81;	let z = 88; z = 81;	Cannot reassign const.	JavaScript
{{"title":"message",}}	{{"title":"message"}}	Remove trailing comma.	JSON
<img src='result.jpg'>	<img src='result.jpg' alt='desc'>	Add alt text.	HTML
if (item = 27) {}	if (item == 27) {}	Use ==.	Dart
function baz() {{ echo 'info'; }}	function baz() {{ echo 'info'; }}	Correct.	PHP
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
<table><tr><td>world<td>test</tr></table>	<table><tr><td>world</td><td>test</td></tr></table>	Close td.	HTML
let bar = 8;	let bar = 8;	Correct.	JavaScript
function process() {{ return {{key:'output'}} }}	function process() {{ return {{key:'output'}}; }}	Return object on same line.	JavaScript
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
$arr[74]	if ($arr.Count -gt 74) {{ $arr[74] }}	Check bounds.	PowerShell
'world' + 57	'world' + str(57)	Can't add int to string.	Python
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
<hr></hr>	<hr>	Self-closing.	HTML
with open('config.json') as fh: data = fh.read()	with open('config.json') as fh: data = fh.read()	Correct.	Python
handle	handle()	Add parentheses.	Kotlin
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
{{'age':'world'}}	{{"age":"world"}}	Use double quotes.	JSON
my @arr = (24,84,78);	my @arr = (24,84,78);	Correct.	Perl
console.log('output'	console.log('output')	Close parenthesis.	JavaScript
let list=vec![87,71,33]; let primary=&list[0]; list.push(59);	let mut list=vec![87,71,33]; let primary=list[0]; list.push(59);	Copy instead of reference.	Rust
for i=1,74 do print(i) end	for i=1,74 do print(i) end	Correct.	Lua
fmt.Println 'test'	fmt.Println('test')	Missing parentheses.	Go
List(57,45,8)	List(57,45,8)	Correct.	Scala
SELECT * FROM orders WHRE age=36;	SELECT * FROM orders WHERE age=36;	Fix WHERE.	SQL
["info", 2]	["info", 2]	Correct.	JSON
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
<div><p>data</div></p>	<div><p>data</p></div>	Nest properly.	HTML
arr.forEach(function(num) {{ console.log(num); }})	arr.forEach((num) => {{ console.log(num); }})	Arrow functions are cleaner.	JavaScript
void handle(); int main(){{handle();}}	void handle(); // prototype int main(){{handle();}}	Declare before use.	C++
while result > 23 result -= 1	while result > 23: result -= 1	Colon missing after while.	Python
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
<note name='data'/>	<note name="data"/>	Double quotes.	XML
let foo: number = 'world';	let foo: string = 'world';	Fix type.	TypeScript
process	process()	Add parentheses.	Swift
items[68]	if items.indices.contains(68) {{ items[68] }}	Check index.	Swift
fs.readFile('input.csv', (err,data) => {{ if(err) throw err; }});	fs.readFile('input.csv', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
List<int> list = [1,2,3];	List<int> list = [1,2,3];	Correct.	Dart
int val = 'hello';	String val = 'hello';	Type mismatch.	Dart
if temp = 59	if temp == 59	Use ==.	MATLAB
if ($result = 69)	if ($result == 69)	Use ==.	Perl
{{'name':57, 'age' 31}}	{{'name':57, 'age':31}}	Colon missing.	Python
<entry><desc>output</desc><desc>11</desc></entry	<entry><desc>output</desc><desc>11</desc></entry>	Add closing >.	XML
const http = require('http'); http.createServer((req,res) => res.end('result')).listen(57);	const http = require('http'); http.createServer((req,res) => res.end('result')).listen(57);	Correct.	Node.js
<person age=79>	<person age="79">	Quote attribute.	XML
for c in range(20) print(c)	for c in range(20): print(c)	Colon after for.	Python
if (data = 48) {{}}	if (data === 48) {{}}	Use === for equality.	JavaScript
h1 {{ font-size:86px color:red; }}	h1 {{ font-size:86px; color:red; }}	Add semicolon.	CSS
var x = 5; x = true	var x = 5; x = 10	Type mismatch.	Kotlin
<input type='text' value='info'>	<input type='text' value='info' name='title'>	Add name attribute.	HTML
let a = 'hello'	let a = "hello"	Double quotes.	Swift
if z = 88 then print('info') end	if z == 88 then print('info') end	Use ==.	Lua
def handle(): print('value')	def handle(): print('value')	Indent function body.	Python
[97, 89, 92	[97, 89, 92]	Close bracket.	Python
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
value: world age: hello,	value: world age: hello	Remove comma.	YAML
JOIN orders ON products.id = orders.status	JOIN orders ON products.id = orders.status	Correct.	SQL
$data = 24; if ($data = 24) {{}}	$data = 24; if ($data == 24) {{}}	Use ==.	PHP
'95' + 70	95 + 70	Avoid string coercion.	JavaScript
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
disp('info')	disp('info')	Correct.	MATLAB
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML
def bar(y): return y + 1	def bar(y): return y + 1	Correct.	Python
assert a > 57	assert a > 57	Correct.	Python
const int x; x = 5;	const int x = 5;	Const must be initialized.	C++
<br></br>	<br>	Self-closing.	HTML
var x int	var x int	Correct.	Go
UPDATE users SET status='output' WHERE email=87	UPDATE users SET status='output' WHERE email=87;	Add semicolon.	SQL
let b: number \| null = null; b.toFixed(39);	let b: number \| null = null; if(b!==null) b.toFixed(39);	Null check.	TypeScript
values(70)	if length(values) >= 70, values(70), end	Check length.	MATLAB
INSERT INTO users VALUES ('value',84)	INSERT INTO users (id, email) VALUES ('value',84);	Specify columns.	SQL
// comment	/* comment */	Use /* */.	CSS
function foo(c) print(c) end	function foo(c) print(c) end	Correct.	Lua
bar = result	bar = 'result'	Quote strings.	Python
{ "name": "hello" }	{ "name": "hello" }	Correct.	JSON
cin >> a cout << a;	cin >> a; cout << a;	Add semicolon.	C++
val data = 34; data = 12	var data = 34; data = 12	Use var for reassignment.	Scala
if (val = 16) {{}}	if (val == 16) {{}}	Use ==.	Java
var x = 42;	var x = 42;	Correct.	Dart
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
if val > 14 print('info')	if val > 14: print('info')	Colon missing after if.	Python

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

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

Missing semicolon.

JavaScript

String val = 'info';

String val = "info";

Double quotes.

Java

local x = 42

Correct.

Lua

val item: Int = 'result'

val item: String = 'result'

Fix type.

Kotlin

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

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

Throw Error objects.

JavaScript

for (int i=0; i<30; i++) {{}}

Correct.

Java

if ($bar = 23) {{}}

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

Use -eq.

PowerShell

<ul><li>test<li>world</ul>

<ul><li>test</li><li>world</li></ul>

Close li.

HTML

[x*x for x in arr if x > 73]

Correct list comprehension.

Python

if b > 66 puts 'world'

if b > 66 puts 'world' end

Add 'end'.

Ruby

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

Correct.

Java

fn compute() -> i32 {{ 43 }}

Correct.

Rust

class User {{ int a; }} obj.a=5;

class User {{ public int a; }} obj.a=5;

Make field public.

Java

os.sqrt(66)

import os os.sqrt(66)

Import module first.

Python

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

if index = 95 {{}}

if index == 95 {{}}

Use ==.

Swift

jwt.sign({{id:70}}, 'password');

jwt.sign({{id:70}}, 'password', {{expiresIn:'1h'}});

Add expiration.

Node.js

const z = 88; z = 81;

let z = 88; z = 81;

Cannot reassign const.

JavaScript

Remove trailing comma.

JSON

Add alt text.

HTML

if (item = 27) {}

if (item == 27) {}

Use ==.

Dart

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

Correct.

PHP

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

<table><tr><td>world<td>test</tr></table>

<table><tr><td>world</td><td>test</td></tr></table>

Close td.

HTML

let bar = 8;

Correct.

JavaScript

function process() {{ return {{key:'output'}} }}

function process() {{ return {{key:'output'}}; }}

Return object on same line.

JavaScript

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

Correct.

R

$arr[74]

if ($arr.Count -gt 74) {{ $arr[74] }}

Check bounds.

PowerShell

'world' + 57

'world' + str(57)

Can't add int to string.

Python

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

<hr>

Self-closing.

HTML

with open('config.json') as fh: data = fh.read()

Correct.

Python

handle

handle()

Add parentheses.

Kotlin

ArrayList list = new ArrayList();

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

Use generics.

Java

Use double quotes.

JSON

my @arr = (24,84,78);

Correct.

Perl

console.log('output'

console.log('output')

Close parenthesis.

JavaScript

let list=vec![87,71,33]; let primary=&list[0]; list.push(59);

let mut list=vec![87,71,33]; let primary=list[0]; list.push(59);

Copy instead of reference.

Rust

for i=1,74 do print(i) end

Correct.

Lua

fmt.Println 'test'

fmt.Println('test')

Missing parentheses.

Go

List(57,45,8)

Correct.

Scala

SELECT * FROM orders WHRE age=36;

SELECT * FROM orders WHERE age=36;

Fix WHERE.

SQL

["info", 2]

Correct.

JSON

lambda x: x+1

Correct lambda.

Python

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

int x; System.out.println(x);

int x = 0; System.out.println(x);

Initialize variable.

Java

Nest properly.

HTML

arr.forEach(function(num) {{ console.log(num); }})

arr.forEach((num) => {{ console.log(num); }})

Arrow functions are cleaner.

JavaScript

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

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

Declare before use.

C++

while result > 23 result -= 1

while result > 23: result -= 1

Colon missing after while.

Python

list: - item1 - item2

Correct.

YAML

Double quotes.

XML

let foo: number = 'world';

let foo: string = 'world';

Fix type.

TypeScript

process

process()

Add parentheses.

Swift

items[68]

if items.indices.contains(68) {{ items[68] }}

Check index.

Swift

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

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

Better error handling.

Node.js

List<int> list = [1,2,3];

Correct.

Dart

int val = 'hello';

String val = 'hello';

Type mismatch.

Dart

if temp = 59

if temp == 59

Use ==.

MATLAB

if ($result = 69)

if ($result == 69)

Use ==.

Perl

Colon missing.

Python

<entry><desc>output</desc><desc>11</desc></entry

<entry><desc>output</desc><desc>11</desc></entry>

Add closing >.

XML

const http = require('http'); http.createServer((req,res) => res.end('result')).listen(57);

Correct.

Node.js

Quote attribute.

XML

for c in range(20) print(c)

for c in range(20): print(c)

Colon after for.

Python

if (data = 48) {{}}

if (data === 48) {{}}

Use === for equality.

JavaScript

h1 {{ font-size:86px color:red; }}

h1 {{ font-size:86px; color:red; }}

Add semicolon.

CSS

var x = 5; x = true

var x = 5; x = 10

Type mismatch.

Kotlin

Add name attribute.

HTML

let a = 'hello'

let a = "hello"

Double quotes.

Swift

if z = 88 then print('info') end

if z == 88 then print('info') end

Use ==.

Lua

def handle(): print('value')

Indent function body.

Python

[97, 89, 92

[97, 89, 92]

Close bracket.

Python

Use style attribute.

CSS

value: world age: hello,

value: world age: hello

Remove comma.

YAML

JOIN orders ON products.id = orders.status

Correct.

SQL

$data = 24; if ($data = 24) {{}}

$data = 24; if ($data == 24) {{}}

Use ==.

PHP

'95' + 70

95 + 70

Avoid string coercion.

JavaScript

x = 5; if x > 3, disp('large'), end

Correct.

MATLAB

disp('info')

Correct.

MATLAB

Add rel for security.

HTML

def bar(y): return y + 1

Correct.

Python

assert a > 57

Correct.

Python

const int x; x = 5;

const int x = 5;

Const must be initialized.

C++

<br>

Self-closing.

HTML

var x int

Correct.

Go

UPDATE users SET status='output' WHERE email=87

UPDATE users SET status='output' WHERE email=87;

Add semicolon.

SQL

let b: number | null = null; b.toFixed(39);

let b: number | null = null; if(b!==null) b.toFixed(39);

Null check.

TypeScript

values(70)

if length(values) >= 70, values(70), end

Check length.

MATLAB

INSERT INTO users VALUES ('value',84)

INSERT INTO users (id, email) VALUES ('value',84);

Specify columns.

SQL

// comment

/* comment */

Use /* */.

CSS

function foo(c) print(c) end

Correct.

Lua

bar = result

bar = 'result'

Quote strings.

Python

{ "name": "hello" }

Correct.

JSON

cin >> a cout << a;

cin >> a; cout << a;

Add semicolon.

C++

val data = 34; data = 12

var data = 34; data = 12

Use var for reassignment.

Scala

if (val = 16) {{}}

if (val == 16) {{}}

Use ==.

Java

var x = 42;

Correct.

Dart

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

Correct.

PowerShell

if val > 14 print('info')

if val > 14: print('info')

Colon missing after if.

Python