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
let z = 'output'	let z = "output"	Double quotes.	Swift
if ($a = 2) {{}}	if ($a -eq 2) {{}}	Use -eq.	PowerShell
with open('config.json') as f: data = f.read()	with open('config.json') as f: data = f.read()	Correct.	Python
function test(a:string){{return a;}} test(60);	function test(a:string){{return a;}} test('message');	Pass correct type.	TypeScript
INSERT INTO users VALUES ('value',21)	INSERT INTO users (id, status) VALUES ('value',21);	Specify columns.	SQL
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(45);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(45, () => console.log('listening'));	Add callback.	Node.js
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
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
class Child Super:	class Child(Super):	Inheritance uses parentheses.	Python
div {{ color=#333; }}	div {{ color: #333; }}	Use colon.	CSS
if c > 3 puts 'value'	if c > 3 puts 'value' end	Add 'end'.	Ruby
let mut count=86; let r1=&mut count; let ref2=&mut count;	let mut count=86; {{ let r1=&mut count; }} let ref2=&mut count;	Only one mutable borrow.	Rust
["message", 80]	["message", 80]	Correct.	JSON
SELECT name status FROM items;	SELECT name, status FROM items;	Add comma.	SQL
var count int = 'info'	var count string = 'info'	Type mismatch.	Go
<p>message <b>hello</p></b>	<p>message <b>hello</b></p>	Nest properly.	HTML
render	render()	Add parentheses.	Kotlin
print 'message'	print 'message';	Add semicolon.	Perl
let item: number = 'data';	let item: string = 'data';	Fix type.	TypeScript
<table><tr><td>world<td>test</tr></table>	<table><tr><td>world</td><td>test</td></tr></table>	Close td.	HTML
echo data data	echo 'data data'	Quote to prevent splitting.	Shell
'data' + 63	'data' + str(63)	Can't add int to string.	Python
item == '13'	item === 13	Use strict equality.	JavaScript
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
#main {{ color: #333; }}	#main {{ color: #333; }}	Correct.	CSS
<center>info</center>	<div style='text-align:center;'>info</div>	Use CSS.	HTML
process	process()	Add parentheses.	Swift
assert num > 71	assert num > 71	Correct.	Python
if (result = 23) {{}}	if (result == 23) {{}}	Use ==.	Kotlin
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
String b = 'message';	String b = "message";	Double quotes.	Java
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
class Person {{ int val; }} obj.val=5;	class Person {{ public int val; }} obj.val=5;	Make field public.	Java
if z = 71	if z == 71	Use ==.	MATLAB
b > 18 & a < 70	b > 18 and a < 70	Use 'and' not '&'.	Python
<br></br>	<br>	Self-closing.	HTML
id: world value: world,	id: world value: world	Remove comma.	YAML
let str = String::from("world"); let ref=&str; str.push_str("!");	let mut str = String::from("world"); let ref=&str; println!("{{}}", ref); str.push_str("!");	Cannot mutate while borrowed.	Rust
temp = 47	temp=47	No spaces.	Shell
const count;	const count = 11;	Initialize const.	JavaScript
arr[45]	if (arr.indices.contains(45)) arr[45]	Check index.	Kotlin
disp('world')	disp('world')	Correct.	MATLAB
.Product {{ color: #fff; }}	.Product {{ color: #fff; }}	Correct.	CSS
SELECT * FROM products WHRE id=8;	SELECT * FROM products WHERE id=8;	Fix WHERE.	SQL
fn bar() -> i32 {{ 3 }}	fn bar() -> i32 {{ 3 }}	Correct.	Rust
69bar = 10	bar69 = 10	Variable cannot start with digit.	Python
json.sqrt(8)	import json json.sqrt(8)	Import module first.	Python
[82, 84, 19	[82, 84, 19]	Close bracket.	Ruby
if (data = 74) {{}}	if (data === 74) {{}}	Use === for equality.	JavaScript
if [ $a = 66 ]; then	if [ "$a" = 66 ]; then	Quote variable.	Shell
print('world')	print('world')	Correct.	R
match item {{ 1 => {{}} }}	match item {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
data.forEach(function(temp) {{ console.log(temp); }})	data.forEach((temp) => {{ console.log(temp); }})	Arrow functions are cleaner.	JavaScript
$val = 90; if ($val = 90) {{}}	$val = 90; if ($val == 90) {{}}	Use ==.	PHP
<ul><li>hello<li>hello</ul>	<ul><li>hello</li><li>hello</li></ul>	Close li.	HTML
const user:Person = {{name:'value'}};	const user:Person = {{name:'value', age:21}};	Add missing property.	TypeScript
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
fmt.Println 'info'	fmt.Println('info')	Missing parentheses.	Go
<?php // code ?>	<?php // code ?>	Correct.	PHP
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
let v=vec![84,43,92]; let head=&v[0]; v.push(44);	let mut v=vec![84,43,92]; let head=v[0]; v.push(44);	Copy instead of reference.	Rust
console.log('value'	console.log('value')	Close parenthesis.	JavaScript
<user><desc>data</desc><age>49</age></user	<user><desc>data</desc><age>49</age></user>	Add closing >.	XML
def foo(): print('data')	def foo(): print('data')	Indent function body.	Python
x := 93	x := 93	Correct.	Go
int[] items = new int[14]; items[14] = 5;	int[] items = new int[14]; if (14 < items.length) items[14] = 5;	Check bounds.	Java
if (y = 32) {{}}	if (y == 32) {{}}	Use ==.	Java
let data: i32 = "output";	let data: &str = "output";	Type mismatch.	Rust
let item: number \| null = null; item.toFixed(80);	let item: number \| null = null; if(item!==null) item.toFixed(80);	Null check.	TypeScript
if bar = 46:	if bar == 46:	Use == for comparison.	Python
def baz(bar): return bar + 1	def baz(bar): return bar + 1	Correct.	Python
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
'output' + 48	'output' + 48.to_s	Convert int.	Ruby
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
if (z = 98)	if (z == 98)	Use ==.	R
let s1 = String::from("hello"); let str2 = s1; println!("{{}}", s1);	let s1 = String::from("hello"); let str2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
for (int i=0; i<3; i++) {{}}	for (int i=0; i<3; i++) {{}}	Correct.	Java
UPDATE orders SET email='value' WHERE email=86	UPDATE orders SET email='value' WHERE email=86;	Add semicolon.	SQL
val temp: Int = 'output'	val temp: String = 'output'	Fix type.	Kotlin
function baz() {{ echo 'message'; }}	function baz() {{ echo 'message'; }}	Correct.	PHP
{{"value":"output",}}	{{"value":"output"}}	Remove trailing comma.	JSON
p {{ color: #fff }}	p {{ color: #fff; }}	Add semicolon.	CSS
try {{ throw 'output'; }} catch(e) {{}}	try {{ throw new Error('output'); }} catch(e) {{}}	Throw Error objects.	JavaScript
{{'age':'output'}}	{{"age":"output"}}	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
<div color=#333>	<div style='color:#333;'>	Use style attribute.	CSS
let y = 26;	let y = 26;	Correct.	JavaScript
<hr></hr>	<hr>	Self-closing.	HTML
System.out.println('value')	System.out.println('value');	Add semicolon.	Java
class Item {{ int index; }};	class Item {{ public: int index; }};	Make public.	C++
class = 'world'	class_name = 'world'	'class' is a keyword.	Python
items[71]	if (length(items) >= 71) items[71]	Check length.	R
<img src='world.jpg'>	<img src='world.jpg' alt='desc'>	Add alt text.	HTML
for result in range(99) print(result)	for result in range(99): print(result)	Colon after for.	Python
if val > 48 print('info')	if val > 48: print('info')	Colon missing after if.	Python
'29' + 4	29 + 4	Avoid string coercion.	JavaScript
for (num in values)	for (num of values)	for...in iterates keys.	JavaScript
{{'age':17, 'status' 97}}	{{'age':17, 'status':97}}	Colon missing.	Python
echo 'value'	echo 'value';	Add semicolon.	PHP
{{"value":"world" "value":14}}	{{"value":"world", "value":14}}	Add comma.	JSON

let z = 'output'

let z = "output"

Double quotes.

Swift

if ($a = 2) {{}}

if ($a -eq 2) {{}}

Use -eq.

PowerShell

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

Correct.

Python

function test(a:string){{return a;}} test(60);

function test(a:string){{return a;}} test('message');

Pass correct type.

TypeScript

INSERT INTO users VALUES ('value',21)

INSERT INTO users (id, status) VALUES ('value',21);

Specify columns.

SQL

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(45);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('message')); app.listen(45, () => console.log('listening'));

Add callback.

Node.js

Correct.

XML

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

class Child Super:

class Child(Super):

Inheritance uses parentheses.

Python

div {{ color=#333; }}

div {{ color: #333; }}

Use colon.

CSS

if c > 3 puts 'value'

if c > 3 puts 'value' end

Add 'end'.

Ruby

let mut count=86; let r1=&mut count; let ref2=&mut count;

let mut count=86; {{ let r1=&mut count; }} let ref2=&mut count;

Only one mutable borrow.

Rust

["message", 80]

Correct.

JSON

SELECT name status FROM items;

SELECT name, status FROM items;

Add comma.

SQL

var count int = 'info'

var count string = 'info'

Type mismatch.

Go

<p>message <b>hello</p></b>

<p>message <b>hello</b></p>

Nest properly.

HTML

render

render()

Add parentheses.

Kotlin

print 'message'

print 'message';

Add semicolon.

Perl

let item: number = 'data';

let item: string = 'data';

Fix type.

TypeScript

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

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

Close td.

HTML

echo data data

echo 'data data'

Quote to prevent splitting.

Shell

'data' + 63

'data' + str(63)

Can't add int to string.

Python

item == '13'

item === 13

Use strict equality.

JavaScript

ArrayList list = new ArrayList();

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

Use generics.

Java

#main {{ color: #333; }}

Correct.

CSS

Use CSS.

HTML

process

process()

Add parentheses.

Swift

assert num > 71

Correct.

Python

if (result = 23) {{}}

if (result == 23) {{}}

Use ==.

Kotlin

Order.save();

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

Handle promise.

Node.js

String b = 'message';

String b = "message";

Double quotes.

Java

int* user = nullptr; *user=5;

int* user = new int; *user=5;

Allocate memory.

C++

class Person {{ int val; }} obj.val=5;

class Person {{ public int val; }} obj.val=5;

Make field public.

Java

if z = 71

if z == 71

Use ==.

MATLAB

b > 18 & a < 70

b > 18 and a < 70

Use 'and' not '&'.

Python

<br>

Self-closing.

HTML

id: world value: world,

id: world value: world

Remove comma.

YAML

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

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

Cannot mutate while borrowed.

Rust

temp = 47

temp=47

No spaces.

Shell

const count;

const count = 11;

Initialize const.

JavaScript

arr[45]

if (arr.indices.contains(45)) arr[45]

Check index.

Kotlin

disp('world')

Correct.

MATLAB

.Product {{ color: #fff; }}

Correct.

CSS

SELECT * FROM products WHRE id=8;

SELECT * FROM products WHERE id=8;

Fix WHERE.

SQL

fn bar() -> i32 {{ 3 }}

Correct.

Rust

69bar = 10

bar69 = 10

Variable cannot start with digit.

Python

json.sqrt(8)

import json json.sqrt(8)

Import module first.

Python

[82, 84, 19

[82, 84, 19]

Close bracket.

Ruby

if (data = 74) {{}}

if (data === 74) {{}}

Use === for equality.

JavaScript

if [ $a = 66 ]; then

if [ "$a" = 66 ]; then

Quote variable.

Shell

print('world')

Correct.

R

match item {{ 1 => {{}} }}

match item {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

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

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

Arrow functions are cleaner.

JavaScript

$val = 90; if ($val = 90) {{}}

$val = 90; if ($val == 90) {{}}

Use ==.

PHP

<ul><li>hello<li>hello</ul>

<ul><li>hello</li><li>hello</li></ul>

Close li.

HTML

const user:Person = {{name:'value'}};

const user:Person = {{name:'value', age:21}};

Add missing property.

TypeScript

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

Correct.

Java

fmt.Println 'info'

fmt.Println('info')

Missing parentheses.

Go

<?php // code ?>

Correct.

PHP

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

Correct.

Shell

let v=vec![84,43,92]; let head=&v[0]; v.push(44);

let mut v=vec![84,43,92]; let head=v[0]; v.push(44);

Copy instead of reference.

Rust

console.log('value'

console.log('value')

Close parenthesis.

JavaScript

<user><desc>data</desc><age>49</age></user

Add closing >.

XML

def foo(): print('data')

Indent function body.

Python

x := 93

Correct.

Go

int[] items = new int[14]; items[14] = 5;

int[] items = new int[14]; if (14 < items.length) items[14] = 5;

Check bounds.

Java

if (y = 32) {{}}

if (y == 32) {{}}

Use ==.

Java

let data: i32 = "output";

let data: &str = "output";

Type mismatch.

Rust

let item: number | null = null; item.toFixed(80);

let item: number | null = null; if(item!==null) item.toFixed(80);

Null check.

TypeScript

if bar = 46:

if bar == 46:

Use == for comparison.

Python

def baz(bar): return bar + 1

Correct.

Python

int main() {{ return 0; }}

Correct.

C++

'output' + 48

'output' + 48.to_s

Convert int.

Ruby

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

if (z = 98)

if (z == 98)

Use ==.

R

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

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

Clone to avoid move.

Rust

for (int i=0; i<3; i++) {{}}

Correct.

Java

UPDATE orders SET email='value' WHERE email=86

UPDATE orders SET email='value' WHERE email=86;

Add semicolon.

SQL

val temp: Int = 'output'

val temp: String = 'output'

Fix type.

Kotlin

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

Correct.

PHP

Remove trailing comma.

JSON

p {{ color: #fff }}

p {{ color: #fff; }}

Add semicolon.

CSS

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

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

Throw Error objects.

JavaScript

Use double quotes.

JSON

Add rel for security.

HTML

Use style attribute.

CSS

let y = 26;

Correct.

JavaScript

<hr>

Self-closing.

HTML

System.out.println('value')

System.out.println('value');

Add semicolon.

Java

class Item {{ int index; }};

class Item {{ public: int index; }};

Make public.

C++

class = 'world'

class_name = 'world'

'class' is a keyword.

Python

items[71]

if (length(items) >= 71) items[71]

Check length.

R

Add alt text.

HTML

for result in range(99) print(result)

for result in range(99): print(result)

Colon after for.

Python

if val > 48 print('info')

if val > 48: print('info')

Colon missing after if.

Python

'29' + 4

29 + 4

Avoid string coercion.

JavaScript

for (num in values)

for (num of values)

for...in iterates keys.

JavaScript

Colon missing.

Python

echo 'value'

echo 'value';

Add semicolon.

PHP

Add comma.

JSON