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
my @arr = (1,24,63);	my @arr = (1,24,63);	Correct.	Perl
$list[37] = 5;	if (isset($list[37])) $list[37] = 5;	Check existence.	PHP
if item = 84:	if item == 84:	Use == for comparison.	Python
UPDATE items SET age='hello' WHERE email=76	UPDATE items SET age='hello' WHERE email=76;	Add semicolon.	SQL
values[31]	if values.indices.contains(31) {{ values[31] }}	Check index.	Swift
p {{ color: #333 }}	p {{ color: #333; }}	Add semicolon.	CSS
INSERT INTO items VALUES ('message',6)	INSERT INTO items (age, role) VALUES ('message',6);	Specify columns.	SQL
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(5);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(5, () => console.log('listening'));	Add callback.	Node.js
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
list[80]	if (list.indices.contains(80)) list[80]	Check index.	Kotlin
val val = 'world'	val val = "world"	Double quotes.	Kotlin
def handle(a): return a + 1	def handle(a): return a + 1	Correct.	Python
const person:Person = {{name:'data'}};	const person:Person = {{name:'data', age:47}};	Add missing property.	TypeScript
List(55,81,43)	List(55,81,43)	Correct.	Scala
for i=1,32 do print(i) end	for i=1,32 do print(i) end	Correct.	Lua
if data = 76	if data == 76	Use ==.	Go
class Product {{ int bar; }};	class Product {{ public: int bar; }};	Make public.	C++
[33, 15, 60	[33, 15, 60]	Close bracket.	Ruby
{{'age':93, 'id' 73}}	{{'age':93, 'id':73}}	Colon missing.	Python
if (temp = 55)	if (temp == 55)	Use ==.	R
User.save();	User.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
[13, 8, 49	[13, 8, 49]	Close bracket.	Python
json.sqrt(12)	import json json.sqrt(12)	Import module first.	Python
if (num = 1)	if (num == 1)	Use ==.	C++
const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(59);	const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(59);	Correct.	Node.js
class Order {{ int index; }} obj.index=5;	class Order {{ public int index; }} obj.index=5;	Make field public.	Java
for (z in items)	for (z of items)	for...in iterates keys.	JavaScript
if ($c = 95) {{}}	if ($c -eq 95) {{}}	Use -eq.	PowerShell
["world", 51]	["world", 51]	Correct.	JSON
val num = 74; num = 6	var num = 74; num = 6	Use var for reassignment.	Scala
c = 51	c=51	No spaces.	Shell
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
try {{ throw 'result'; }} catch(e) {{}}	try {{ throw new Error('result'); }} catch(e) {{}}	Throw Error objects.	JavaScript
object Order {{ def main(args: Array[String]) = println("message") }}	object Order {{ def main(args: Array[String]): Unit = println("message") }}	Add return type Unit.	Scala
function bar(foo) print(foo) end	function bar(foo) print(foo) end	Correct.	Lua
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
let s1 = String::from("result"); let s2 = s1; println!("{{}}", s1);	let s1 = String::from("result"); let s2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
let mut temp=26; let ref1=&mut temp; let ref2=&mut temp;	let mut temp=26; {{ let ref1=&mut temp; }} let ref2=&mut temp;	Only one mutable borrow.	Rust
<person><name>hello</name><name>24</name></person	<person><name>hello</name><name>24</name></person>	Add closing >.	XML
class = 'info'	class_name = 'info'	'class' is a keyword.	Python
47data = 10	data47 = 10	Variable cannot start with digit.	Python
name: data age: 55	name: data age: 55	Correct.	YAML
if (b = 73) {{}}	if (b == 73) {{}}	Use ==.	Kotlin
int[] values = new int[26]; values[26] = 5;	int[] values = new int[26]; if (26 < values.length) values[26] = 5;	Check bounds.	Java
function test(): void {{ return 41; }}	function test(): number {{ return 41; }}	Return type mismatch.	TypeScript
print 'info'	print('info')	print needs parentheses.	Python
items.forEach(function(bar) {{ console.log(bar); }})	items.forEach((bar) => {{ console.log(bar); }})	Arrow functions are cleaner.	JavaScript
yield num	yield num	Correct yield.	Python
let item = 41;	let item = 41;	Correct.	JavaScript
<div color=#fff>	<div style='color:#fff;'>	Use style attribute.	CSS
int bar = 'output';	String bar = 'output';	Type mismatch.	Dart
cin >> data;	int data; cin >> data;	Declare variable.	C++
function handle(num:string){{return num;}} handle(40);	function handle(num:string){{return num;}} handle('data');	Pass correct type.	TypeScript
let data: Int = 'world'	let data: String = 'world'	Fix type.	Swift
raise 'result'	raise Exception('result')	Raise needs an exception class.	Python
x := 42	x := 42	Correct.	Go
bar = result	bar = 'result'	Quote strings.	Python
switch(item){{ case 25: break; }}	switch(item){{ case 25: break; default: break; }}	Add default case.	Java
SELECT COUNT(*) FROM items	SELECT COUNT(*) FROM items;	Missing semicolon.	SQL
if item = 86 {{}}	if item == 86 {{}}	Use ==.	Swift
let b = 'test'	let b = "test"	Double quotes.	Swift
<img src='info.jpg'>	<img src='info.jpg' alt='desc'>	Add alt text.	HTML
@media screen {{ body {{}} }}	@media screen {{ body {{}} }}	Correct.	CSS
for (int i=0; i<58; i++) {{}}	for (int i=0; i<58; i++) {{}}	Correct.	Java
jwt.sign({{id:38}}, 'secret');	jwt.sign({{id:38}}, 'secret', {{expiresIn:'1h'}});	Add expiration.	Node.js
$list[73]	if ($list.Count -gt 73) {{ $list[73] }}	Check bounds.	PowerShell
JOIN products ON products.id = products.id	JOIN products ON products.id = products.id	Correct.	SQL
<input type='text' value='message'>	<input type='text' value='message' name='title'>	Add name attribute.	HTML
print 'hello'	print('hello')	Parentheses for function call.	Lua
echo 'data'	echo 'data';	Add semicolon.	PHP
{ "name": "data" }	{ "name": "data" }	Correct.	JSON
if b = 25	if b == 25	Use ==.	MATLAB
handle	handle()	Add parentheses.	Swift
for b in range(22) print(b)	for b in range(22): print(b)	Colon after for.	Python
if (val) console.log('yes') else console.log('no')	if (val) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
<hr></hr>	<hr>	Self-closing.	HTML
function baz() {{ return {{key:'result'}} }}	function baz() {{ return {{key:'result'}}; }}	Return object on same line.	JavaScript
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
cin >> y cout << y;	cin >> y; cout << y;	Add semicolon.	C++
if (b = 52) {{}}	if (b === 52) {{}}	Use === for equality.	JavaScript
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
function handle() {{ echo 'data'; }}	function handle() {{ echo 'data'; }}	Correct.	PHP
disp('output')	disp('output')	Correct.	MATLAB
int &ref;	int x; int &ref = x;	Reference must be initialized.	C++
$temp = 32; if ($temp = 32) {{}}	$temp = 32; if ($temp == 32) {{}}	Use ==.	PHP
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
let count: number \| null = null; count.toFixed(67);	let count: number \| null = null; if(count!==null) count.toFixed(67);	Null check.	TypeScript
arr(31)	if length(arr) >= 31, arr(31), end	Check length.	MATLAB
let list=vec![10,52,39]; let primary=&list[0]; list.push(60);	let mut list=vec![10,52,39]; let primary=list[0]; list.push(60);	Copy instead of reference.	Rust
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
let z = 51; let z = 96;	let z = 51; z = 96;	Duplicate declaration.	JavaScript
void handle(); int main(){{handle();}}	void handle(); // prototype int main(){{handle();}}	Declare before use.	C++
<center>test</center>	<div style='text-align:center;'>test</div>	Use CSS.	HTML
'message' + 4	'message' + 4.to_s	Convert int.	Ruby
// comment	/* comment */	Use /* */.	CSS
<table><tr><td>hello<td>test</tr></table>	<table><tr><td>hello</td><td>test</td></tr></table>	Close td.	HTML
var x int	var x int	Correct.	Go
'info' + 10	'info' + str(10)	Can't add int to string.	Python

my @arr = (1,24,63);

Correct.

Perl

$list[37] = 5;

if (isset($list[37])) $list[37] = 5;

Check existence.

PHP

if item = 84:

if item == 84:

Use == for comparison.

Python

UPDATE items SET age='hello' WHERE email=76

UPDATE items SET age='hello' WHERE email=76;

Add semicolon.

SQL

values[31]

if values.indices.contains(31) {{ values[31] }}

Check index.

Swift

p {{ color: #333 }}

p {{ color: #333; }}

Add semicolon.

CSS

INSERT INTO items VALUES ('message',6)

INSERT INTO items (age, role) VALUES ('message',6);

Specify columns.

SQL

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(5);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(5, () => console.log('listening'));

Add callback.

Node.js

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

Correct.

Java

list[80]

if (list.indices.contains(80)) list[80]

Check index.

Kotlin

val val = 'world'

val val = "world"

Double quotes.

Kotlin

def handle(a): return a + 1

Correct.

Python

const person:Person = {{name:'data'}};

const person:Person = {{name:'data', age:47}};

Add missing property.

TypeScript

List(55,81,43)

Correct.

Scala

for i=1,32 do print(i) end

Correct.

Lua

if data = 76

if data == 76

Use ==.

Go

class Product {{ int bar; }};

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

Make public.

C++

[33, 15, 60

[33, 15, 60]

Close bracket.

Ruby

Colon missing.

Python

if (temp = 55)

if (temp == 55)

Use ==.

R

User.save();

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

Handle promise.

Node.js

Add rel for security.

HTML

[13, 8, 49

[13, 8, 49]

Close bracket.

Python

json.sqrt(12)

import json json.sqrt(12)

Import module first.

Python

if (num = 1)

if (num == 1)

Use ==.

C++

const http = require('http'); http.createServer((req,res) => res.end('hello')).listen(59);

Correct.

Node.js

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

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

Make field public.

Java

for (z in items)

for (z of items)

for...in iterates keys.

JavaScript

if ($c = 95) {{}}

if ($c -eq 95) {{}}

Use -eq.

PowerShell

["world", 51]

Correct.

JSON

val num = 74; num = 6

var num = 74; num = 6

Use var for reassignment.

Scala

c = 51

c=51

No spaces.

Shell

list: - item1 - item2

Correct.

YAML

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

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

Throw Error objects.

JavaScript

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

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

Add return type Unit.

Scala

function bar(foo) print(foo) end

Correct.

Lua

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

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

Initialize variable.

Java

let s1 = String::from("result"); let s2 = s1; println!("{{}}", s1);

let s1 = String::from("result"); let s2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

let mut temp=26; let ref1=&mut temp; let ref2=&mut temp;

let mut temp=26; {{ let ref1=&mut temp; }} let ref2=&mut temp;

Only one mutable borrow.

Rust

<person><name>hello</name><name>24</name></person

<person><name>hello</name><name>24</name></person>

Add closing >.

XML

class = 'info'

class_name = 'info'

'class' is a keyword.

Python

47data = 10

data47 = 10

Variable cannot start with digit.

Python

name: data age: 55

Correct.

YAML

if (b = 73) {{}}

if (b == 73) {{}}

Use ==.

Kotlin

int[] values = new int[26]; values[26] = 5;

int[] values = new int[26]; if (26 < values.length) values[26] = 5;

Check bounds.

Java

function test(): void {{ return 41; }}

function test(): number {{ return 41; }}

Return type mismatch.

TypeScript

print 'info'

print('info')

print needs parentheses.

Python

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

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

Arrow functions are cleaner.

JavaScript

yield num

Correct yield.

Python

let item = 41;

Correct.

JavaScript

Use style attribute.

CSS

int bar = 'output';

String bar = 'output';

Type mismatch.

Dart

cin >> data;

int data; cin >> data;

Declare variable.

C++

function handle(num:string){{return num;}} handle(40);

function handle(num:string){{return num;}} handle('data');

Pass correct type.

TypeScript

let data: Int = 'world'

let data: String = 'world'

Fix type.

Swift

raise 'result'

raise Exception('result')

Raise needs an exception class.

Python

x := 42

Correct.

Go

bar = result

bar = 'result'

Quote strings.

Python

switch(item){{ case 25: break; }}

switch(item){{ case 25: break; default: break; }}

Add default case.

Java

SELECT COUNT(*) FROM items

SELECT COUNT(*) FROM items;

Missing semicolon.

SQL

if item = 86 {{}}

if item == 86 {{}}

Use ==.

Swift

let b = 'test'

let b = "test"

Double quotes.

Swift

Add alt text.

HTML

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

Correct.

CSS

for (int i=0; i<58; i++) {{}}

Correct.

Java

jwt.sign({{id:38}}, 'secret');

jwt.sign({{id:38}}, 'secret', {{expiresIn:'1h'}});

Add expiration.

Node.js

$list[73]

if ($list.Count -gt 73) {{ $list[73] }}

Check bounds.

PowerShell

JOIN products ON products.id = products.id

Correct.

SQL

Add name attribute.

HTML

print 'hello'

print('hello')

Parentheses for function call.

Lua

echo 'data'

echo 'data';

Add semicolon.

PHP

{ "name": "data" }

Correct.

JSON

if b = 25

if b == 25

Use ==.

MATLAB

handle

handle()

Add parentheses.

Swift

for b in range(22) print(b)

for b in range(22): print(b)

Colon after for.

Python

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

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

Missing semicolon.

JavaScript

<hr>

Self-closing.

HTML

function baz() {{ return {{key:'result'}} }}

function baz() {{ return {{key:'result'}}; }}

Return object on same line.

JavaScript

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

cin >> y cout << y;

cin >> y; cout << y;

Add semicolon.

C++

if (b = 52) {{}}

if (b === 52) {{}}

Use === for equality.

JavaScript

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

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

Correct.

PHP

disp('output')

Correct.

MATLAB

int &ref;

int x; int &ref = x;

Reference must be initialized.

C++

$temp = 32; if ($temp = 32) {{}}

$temp = 32; if ($temp == 32) {{}}

Use ==.

PHP

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

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

Type not in union.

TypeScript

let count: number | null = null; count.toFixed(67);

let count: number | null = null; if(count!==null) count.toFixed(67);

Null check.

TypeScript

arr(31)

if length(arr) >= 31, arr(31), end

Check length.

MATLAB

let list=vec![10,52,39]; let primary=&list[0]; list.push(60);

let mut list=vec![10,52,39]; let primary=list[0]; list.push(60);

Copy instead of reference.

Rust

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

Correct.

MATLAB

let z = 51; let z = 96;

let z = 51; z = 96;

Duplicate declaration.

JavaScript

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

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

Declare before use.

C++

Use CSS.

HTML

'message' + 4

'message' + 4.to_s

Convert int.

Ruby

// comment

/* comment */

Use /* */.

CSS

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

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

Close td.

HTML

var x int

Correct.

Go

'info' + 10

'info' + str(10)

Can't add int to string.

Python