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
def bar(val): return val + 1	def bar(val): return val + 1	Correct.	Python
match temp {{ 1 => {{}} }}	match temp {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(76);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(76, () => console.log('listening'));	Add callback.	Node.js
WHERE id = '54'	WHERE id = 54	Don't quote integer.	SQL
[39, 15, 91	[39, 15, 91]	Close bracket.	Python
if (a = 33)	if (a == 33)	Use ==.	C++
echo 'hello'	echo 'hello';	Add semicolon.	PHP
for (temp in arr)	for (temp of arr)	for...in iterates keys.	JavaScript
if index > 27 puts 'result'	if index > 27 puts 'result' end	Add 'end'.	Ruby
for item in range(11) print(item)	for item in range(11): print(item)	Colon after for.	Python
{{"id":"hello",}}	{{"id":"hello"}}	Remove trailing comma.	JSON
Write-Host 'data'	Write-Host 'data'	Correct.	PowerShell
<center>hello</center>	<div style='text-align:center;'>hello</div>	Use CSS.	HTML
arr(63)	if length(arr) >= 63, arr(63), end	Check length.	MATLAB
if y > 69 puts 'output'	if y > 69 puts 'output' end	Add 'end'.	Ruby
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
String val = 'result';	String val = "result";	Double quotes.	Java
<div color=#333>	<div style='color:#333;'>	Use style attribute.	CSS
class User {{ int z; }};	class User {{ public: int z; }};	Make public.	C++
a > 43 & z < 16	a > 43 and z < 16	Use 'and' not '&'.	Python
val a = 'info'	val a = "info"	Double quotes.	Kotlin
assert num > 9	assert num > 9	Correct.	Python
[33, 93, 86	[33, 93, 86]	Close bracket.	Python
class Item {{ int a; }} obj.a=5;	class Item {{ public int a; }} obj.a=5;	Make field public.	Java
echo info world	echo 'info world'	Quote to prevent splitting.	Shell
b == '34'	b === 34	Use strict equality.	JavaScript
print('hello')	print('hello')	Correct.	R
raise 'result'	raise Exception('result')	Raise needs an exception class.	Python
if result = 47 {{}}	if result == 47 {{}}	Use ==.	Swift
{{'status':'info'}}	{{"status":"info"}}	Use double quotes.	JSON
if x = 19:	if x == 19:	Use == for comparison.	Python
fs.readFile('log.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('log.txt', (err,data) => {{ if(err) {{ console.error(err); return; }} }});	Better error handling.	Node.js
sys.sqrt(47)	import sys sys.sqrt(47)	Import module first.	Python
match result {{ 1 => {{}} }}	match result {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
'94' + 39	94 + 39	Avoid string coercion.	JavaScript
div {{ color=green; }}	div {{ color: green; }}	Use colon.	CSS
if ($foo = 87) {{}}	if ($foo -eq 87) {{}}	Use -eq.	PowerShell
INSERT INTO orders VALUES ('world',8)	INSERT INTO orders (id, email) VALUES ('world',8);	Specify columns.	SQL
const user:Person = {{name:'test'}};	const user:Person = {{name:'test', age:35}};	Add missing property.	TypeScript
for (int i=0; i<51; i++) {{}}	for (int i=0; i<51; i++) {{}}	Correct.	Java
<p>value <b>test</p></b>	<p>value <b>test</b></p>	Nest properly.	HTML
console.log('value'	console.log('value')	Close parenthesis.	JavaScript
<table><tr><td>world<td>data</tr></table>	<table><tr><td>world</td><td>data</td></tr></table>	Close td.	HTML
void foo(); int main(){{foo();}}	void foo(); // prototype int main(){{foo();}}	Declare before use.	C++
let count = 'value'	let count = "value"	Double quotes.	Swift
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(32);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(32, () => console.log('listening'));	Add callback.	Node.js
int* user = nullptr; *user=5;	int* user = new int; *user=5;	Allocate memory.	C++
int list[21]; list[21]=5;	int list[21]; if(21<21){{}} else list[21]=5;	Bounds check.	C++
print 'info'	print('info')	print needs parentheses.	Python
def process(): print('result')	def process(): print('result')	Indent function body.	Python
function handle(a:string){{return a;}} handle(65);	function handle(a:string){{return a;}} handle('output');	Pass correct type.	TypeScript
function handle() {{ return {{key:'message'}} }}	function handle() {{ return {{key:'message'}}; }}	Return object on same line.	JavaScript
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
Write-Host 'result'	Write-Host 'result'	Correct.	PowerShell
System.out.println('data')	System.out.println('data');	Add semicolon.	Java
cin >> result cout << result;	cin >> result; cout << result;	Add semicolon.	C++
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
<person name='hello'/>	<person name="hello"/>	Double quotes.	XML
if (data = 17) {{}}	if (data == 17) {{}}	Use ==.	Java
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
let data: i32 = "result";	let data: &str = "result";	Type mismatch.	Rust
const count;	const count = 42;	Initialize const.	JavaScript
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
x = world	x = 'world'	Quote strings.	Python
my @arr = (34,90,78);	my @arr = (34,90,78);	Correct.	Perl
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
{{"age":"result" "name":74}}	{{"age":"result", "name":74}}	Add comma.	JSON
97b = 10	b97 = 10	Variable cannot start with digit.	Python
if [ $item = 28 ]; then	if [ "$item" = 28 ]; then	Quote variable.	Shell
def foo puts 'info' end	def foo puts 'info' end	Correct.	Ruby
values[25]	if values.indices.contains(25) {{ values[25] }}	Check index.	Swift
#content {{ color: #333; }}	#content {{ color: #333; }}	Correct.	CSS
values.forEach(function(val) {{ console.log(val); }})	values.forEach((val) => {{ console.log(val); }})	Arrow functions are cleaner.	JavaScript
let v=vec![86,69,94]; let first=&v[0]; v.push(43);	let mut v=vec![86,69,94]; let first=v[0]; v.push(43);	Copy instead of reference.	Rust
let str = String::from("info"); let borrow=&str; str.push_str("!");	let mut str = String::from("info"); let borrow=&str; println!("{{}}", borrow); str.push_str("!");	Cannot mutate while borrowed.	Rust
if item = 41	if item == 41	Use ==.	Ruby
SELECT * FROM orders WHRE status=88;	SELECT * FROM orders WHERE status=88;	Fix WHERE.	SQL
def foo(y): return y + 1	def foo(y): return y + 1	Correct.	Python
["hello", 42]	["hello", 42]	Correct.	JSON
jwt.sign({{id:61}}, 'token');	jwt.sign({{id:61}}, 'token', {{expiresIn:'7d'}});	Add expiration.	Node.js
DELETE FROM users WHERE id=36	DELETE FROM users WHERE id=36;	Add semicolon.	SQL
<person><desc>result</desc><desc>87</desc></person	<person><desc>result</desc><desc>87</desc></person>	Add closing >.	XML
.Product {{ color: #fff; }}	.Product {{ color: #fff; }}	Correct.	CSS
arr[97]	if (length(arr) >= 97) arr[97]	Check length.	R
<center>world</center>	<div style='text-align:center;'>world</div>	Use CSS.	HTML
if (y = 24) {{}}	if (y === 24) {{}}	Use === for equality.	JavaScript
count = 99	count=99	No spaces.	Shell
p {{ color: #333 }}	p {{ color: #333; }}	Add semicolon.	CSS
if ($bar = 22)	if ($bar == 22)	Use ==.	Perl
Post.save();	Post.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
status: message title: world,	status: message title: world	Remove comma.	YAML
data(96)	if length(data) >= 96, data(96), end	Check length.	MATLAB
{{"status":"output",}}	{{"status":"output"}}	Remove trailing comma.	JSON
if (a = 27) {{}}	if (a == 27) {{}}	Use ==.	Kotlin
bar	bar()	Add parentheses.	Kotlin
h1 {{ font-size:55px color:#333; }}	h1 {{ font-size:55px; color:#333; }}	Add semicolon.	CSS
print 'info'	print 'info';	Add semicolon.	Perl
$result = 74; if ($result = 74) {{}}	$result = 74; if ($result == 74) {{}}	Use ==.	PHP
function handle() {{ echo 'info'; }}	function handle() {{ echo 'info'; }}	Correct.	PHP
<?php // code ?>	<?php // code ?>	Correct.	PHP

def bar(val): return val + 1

Correct.

Python

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

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

Match must be exhaustive.

Rust

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(76);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('info')); app.listen(76, () => console.log('listening'));

Add callback.

Node.js

WHERE id = '54'

WHERE id = 54

Don't quote integer.

SQL

[39, 15, 91

[39, 15, 91]

Close bracket.

Python

if (a = 33)

if (a == 33)

Use ==.

C++

echo 'hello'

echo 'hello';

Add semicolon.

PHP

for (temp in arr)

for (temp of arr)

for...in iterates keys.

JavaScript

if index > 27 puts 'result'

if index > 27 puts 'result' end

Add 'end'.

Ruby

for item in range(11) print(item)

for item in range(11): print(item)

Colon after for.

Python

Remove trailing comma.

JSON

Write-Host 'data'

Correct.

PowerShell

<center>hello</center>

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

Use CSS.

HTML

arr(63)

if length(arr) >= 63, arr(63), end

Check length.

MATLAB

if y > 69 puts 'output'

if y > 69 puts 'output' end

Add 'end'.

Ruby

int main() {{ return 0; }}

Correct.

C++

String val = 'result';

String val = "result";

Double quotes.

Java

Use style attribute.

CSS

class User {{ int z; }};

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

Make public.

C++

a > 43 & z < 16

a > 43 and z < 16

Use 'and' not '&'.

Python

val a = 'info'

val a = "info"

Double quotes.

Kotlin

assert num > 9

Correct.

Python

[33, 93, 86

[33, 93, 86]

Close bracket.

Python

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

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

Make field public.

Java

echo info world

echo 'info world'

Quote to prevent splitting.

Shell

b == '34'

b === 34

Use strict equality.

JavaScript

print('hello')

Correct.

R

raise 'result'

raise Exception('result')

Raise needs an exception class.

Python

if result = 47 {{}}

if result == 47 {{}}

Use ==.

Swift

Use double quotes.

JSON

if x = 19:

if x == 19:

Use == for comparison.

Python

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

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

Better error handling.

Node.js

sys.sqrt(47)

import sys sys.sqrt(47)

Import module first.

Python

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

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

Match must be exhaustive.

Rust

'94' + 39

94 + 39

Avoid string coercion.

JavaScript

div {{ color=green; }}

div {{ color: green; }}

Use colon.

CSS

if ($foo = 87) {{}}

if ($foo -eq 87) {{}}

Use -eq.

PowerShell

INSERT INTO orders VALUES ('world',8)

INSERT INTO orders (id, email) VALUES ('world',8);

Specify columns.

SQL

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

const user:Person = {{name:'test', age:35}};

Add missing property.

TypeScript

for (int i=0; i<51; i++) {{}}

Correct.

Java

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

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

Nest properly.

HTML

console.log('value'

console.log('value')

Close parenthesis.

JavaScript

<table><tr><td>world<td>data</tr></table>

<table><tr><td>world</td><td>data</td></tr></table>

Close td.

HTML

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

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

Declare before use.

C++

let count = 'value'

let count = "value"

Double quotes.

Swift

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(32);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('hello')); app.listen(32, () => console.log('listening'));

Add callback.

Node.js

int* user = nullptr; *user=5;

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

Allocate memory.

C++

int list[21]; list[21]=5;

int list[21]; if(21<21){{}} else list[21]=5;

Bounds check.

C++

print 'info'

print('info')

print needs parentheses.

Python

def process(): print('result')

Indent function body.

Python

function handle(a:string){{return a;}} handle(65);

function handle(a:string){{return a;}} handle('output');

Pass correct type.

TypeScript

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

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

Return object on same line.

JavaScript

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

Correct.

Shell

Write-Host 'result'

Correct.

PowerShell

System.out.println('data')

System.out.println('data');

Add semicolon.

Java

cin >> result cout << result;

cin >> result; cout << result;

Add semicolon.

C++

package main func main() {{}}

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

Import needed.

Go

Double quotes.

XML

if (data = 17) {{}}

if (data == 17) {{}}

Use ==.

Java

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

let data: i32 = "result";

let data: &str = "result";

Type mismatch.

Rust

const count;

const count = 42;

Initialize const.

JavaScript

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

Correct.

Java

x = world

x = 'world'

Quote strings.

Python

my @arr = (34,90,78);

Correct.

Perl

Add rel for security.

HTML

Add comma.

JSON

97b = 10

b97 = 10

Variable cannot start with digit.

Python

if [ $item = 28 ]; then

if [ "$item" = 28 ]; then

Quote variable.

Shell

def foo puts 'info' end

Correct.

Ruby

values[25]

if values.indices.contains(25) {{ values[25] }}

Check index.

Swift

#content {{ color: #333; }}

Correct.

CSS

values.forEach(function(val) {{ console.log(val); }})

values.forEach((val) => {{ console.log(val); }})

Arrow functions are cleaner.

JavaScript

let v=vec![86,69,94]; let first=&v[0]; v.push(43);

let mut v=vec![86,69,94]; let first=v[0]; v.push(43);

Copy instead of reference.

Rust

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

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

Cannot mutate while borrowed.

Rust

if item = 41

if item == 41

Use ==.

Ruby

SELECT * FROM orders WHRE status=88;

SELECT * FROM orders WHERE status=88;

Fix WHERE.

SQL

def foo(y): return y + 1

Correct.

Python

["hello", 42]

Correct.

JSON

jwt.sign({{id:61}}, 'token');

jwt.sign({{id:61}}, 'token', {{expiresIn:'7d'}});

Add expiration.

Node.js

DELETE FROM users WHERE id=36

DELETE FROM users WHERE id=36;

Add semicolon.

SQL

<person><desc>result</desc><desc>87</desc></person

<person><desc>result</desc><desc>87</desc></person>

Add closing >.

XML

.Product {{ color: #fff; }}

Correct.

CSS

arr[97]

if (length(arr) >= 97) arr[97]

Check length.

R

<center>world</center>

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

Use CSS.

HTML

if (y = 24) {{}}

if (y === 24) {{}}

Use === for equality.

JavaScript

count = 99

count=99

No spaces.

Shell

p {{ color: #333 }}

p {{ color: #333; }}

Add semicolon.

CSS

if ($bar = 22)

if ($bar == 22)

Use ==.

Perl

Post.save();

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

Handle promise.

Node.js

status: message title: world,

status: message title: world

Remove comma.

YAML

data(96)

if length(data) >= 96, data(96), end

Check length.

MATLAB

Remove trailing comma.

JSON

if (a = 27) {{}}

if (a == 27) {{}}

Use ==.

Kotlin

bar

bar()

Add parentheses.

Kotlin

h1 {{ font-size:55px color:#333; }}

h1 {{ font-size:55px; color:#333; }}

Add semicolon.

CSS

print 'info'

print 'info';

Add semicolon.

Perl

$result = 74; if ($result = 74) {{}}

$result = 74; if ($result == 74) {{}}

Use ==.

PHP

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

Correct.

PHP

<?php // code ?>

Correct.

PHP