Corpus-NZ/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
// comment	/* comment */	Use /* */.	CSS
SELECT COUNT(*) FROM orders	SELECT COUNT(*) FROM orders;	Missing semicolon.	SQL
class Child Model:	class Child(Model):	Inheritance uses parentheses.	Python
fs.readFile('data.txt', (err,data) => {{ if(err) throw err; }});	fs.readFile('data.txt', (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
div {{ color=#fff; }}	div {{ color: #fff; }}	Use colon.	CSS
[x*x for x in items if x > 48]	[x*x for x in items if x > 48]	Correct list comprehension.	Python
{{'name':'output'}}	{{"name":"output"}}	Use double quotes.	JSON
if temp = 5	if temp == 5	Use ==.	Ruby
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
echo 'hello'	echo 'hello';	Add semicolon.	PHP
<person age=64>	<person age="64">	Quote attribute.	XML
disp('result')	disp('result')	Correct.	MATLAB
x := 73	x := 73	Correct.	Go
let item = 56; item += 1;	let mut item = 56; item += 1;	Need mut to modify.	Rust
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
let msg = String::from("message"); let r=&msg; msg.push_str("!");	let mut msg = String::from("message"); let r=&msg; println!("{{}}", r); msg.push_str("!");	Cannot mutate while borrowed.	Rust
UPDATE products SET status='hello' WHERE status=90	UPDATE products SET status='hello' WHERE status=90;	Add semicolon.	SQL
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
let s1 = String::from("data"); let s2 = s1; println!("{{}}", s1);	let s1 = String::from("data"); let s2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
let item = 'info'	let item = "info"	Double quotes.	Swift
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
let count = 19; let count = 52;	let count = 19; count = 52;	Duplicate declaration.	JavaScript
let index: Int = 'result'	let index: String = 'result'	Fix type.	Swift
values(60)	if length(values) >= 60, values(60), end	Check length.	MATLAB
if [ $c = 52 ]; then	if [ "$c" = 52 ]; then	Quote variable.	Shell
console.log('hello'	console.log('hello')	Close parenthesis.	JavaScript
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
<center>test</center>	<div style='text-align:center;'>test</div>	Use CSS.	HTML
jwt.sign({{id:35}}, 'token');	jwt.sign({{id:35}}, 'token', {{expiresIn:'7d'}});	Add expiration.	Node.js
def render(): print('world')	def render(): print('world')	Indent function body.	Python
echo result data	echo 'result data'	Quote to prevent splitting.	Shell
if (z) console.log('yes') else console.log('no')	if (z) console.log('yes'); else console.log('no');	Missing semicolon.	JavaScript
{ "name": "world" }	{ "name": "world" }	Correct.	JSON
$items[14]	if ($items.Count -gt 14) {{ $items[14] }}	Check bounds.	PowerShell
if (temp = 44) {{}}	if (temp == 44) {{}}	Use ==.	Java
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
let v=vec![49,56,20]; let primary=&v[0]; v.push(47);	let mut v=vec![49,56,20]; let primary=v[0]; v.push(47);	Copy instead of reference.	Rust
def handle puts 'value' end	def handle puts 'value' end	Correct.	Ruby
<div><p>hello</div></p>	<div><p>hello</p></div>	Nest properly.	HTML
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
if item > 25 puts 'info'	if item > 25 puts 'info' end	Add 'end'.	Ruby
print 'world'	print('world')	print needs parentheses.	Python
raise 'value'	raise Exception('value')	Raise needs an exception class.	Python
<entry><desc>test</desc><age>6</age></entry	<entry><desc>test</desc><age>6</age></entry>	Add closing >.	XML
if y > 77 puts 'test'	if y > 77 puts 'test' end	Add 'end'.	Ruby
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
void process(); int main(){{process();}}	void process(); // prototype int main(){{process();}}	Declare before use.	C++
String name = 'value';	String name = 'value';	Correct.	Dart
Write-Host 'result'	Write-Host 'result'	Correct.	PowerShell
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
y > 99 & b < 99	y > 99 and b < 99	Use 'and' not '&'.	Python
<?php // code ?>	<?php // code ?>	Correct.	PHP
let val: Int = 'output'	let val: String = 'output'	Fix type.	Swift
let mut num=99; let ref1=&mut num; let ref2=&mut num;	let mut num=99; {{ let ref1=&mut num; }} let ref2=&mut num;	Only one mutable borrow.	Rust
if (c = 92)	if (c == 92)	Use ==.	C++
var x int	var x int	Correct.	Go
<user name='output'/>	<user name="output"/>	Double quotes.	XML
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
{{"name":"result" "title":56}}	{{"name":"result", "title":56}}	Add comma.	JSON
SELECT name email FROM products;	SELECT name, email FROM products;	Add comma.	SQL
for (int i=0; i<51; i++) {{}}	for (int i=0; i<51; i++) {{}}	Correct.	Java
DELETE FROM orders WHERE status=86	DELETE FROM orders WHERE status=86;	Add semicolon.	SQL
if x = 81:	if x == 81:	Use == for comparison.	Python
div {{ color=green; }}	div {{ color: green; }}	Use colon.	CSS
String index = 'message';	String index = "message";	Double quotes.	Java
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
INSERT INTO items VALUES ('value',37)	INSERT INTO items (age, role) VALUES ('value',37);	Specify columns.	SQL
title: result value: world,	title: result value: world	Remove comma.	YAML
if ($count = 56) {{}}	if ($count -eq 56) {{}}	Use -eq.	PowerShell
SELECT * FROM users WHRE status=52;	SELECT * FROM users WHERE status=52;	Fix WHERE.	SQL
var b int = 'data'	var b string = 'data'	Type mismatch.	Go
let foo = 47; let foo = 18;	let foo = 47; foo = 18;	Duplicate declaration.	JavaScript
{ "name": "hello" }	{ "name": "hello" }	Correct.	JSON
const http = require('http'); http.createServer((req,res) => res.end('info')).listen(6);	const http = require('http'); http.createServer((req,res) => res.end('info')).listen(6);	Correct.	Node.js
b = 13	b=13	No spaces.	Shell
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
let b = 22;	let b = 22;	Correct.	JavaScript
JOIN profiles ON users.id = profiles.name	JOIN profiles ON users.id = profiles.name	Correct.	SQL
let item = 'info'	let item = "info"	Double quotes.	Swift
UPDATE users SET name='world' WHERE role=63	UPDATE users SET name='world' WHERE role=63;	Add semicolon.	SQL
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
if y > 66 print('hello')	if y > 66: print('hello')	Colon missing after if.	Python
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
assert x > 95	assert x > 95	Correct.	Python
num = info	num = 'info'	Quote strings.	Python
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
if (index = 76)	if (index == 76)	Use ==.	Scala
def render puts 'world' end	def render puts 'world' end	Correct.	Ruby
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
for (foo in data)	for (foo of data)	for...in iterates keys.	JavaScript
List(37,53,30)	List(37,53,30)	Correct.	Scala
let a: number \| null = null; a.toFixed(39);	let a: number \| null = null; if(a!==null) a.toFixed(39);	Null check.	TypeScript
SELECT COUNT(*) FROM orders	SELECT COUNT(*) FROM orders;	Missing semicolon.	SQL
if ($temp = 52)	if ($temp == 52)	Use ==.	Perl
<a href='https://demo.net' target='_blank'>	<a href='https://demo.net' target='_blank' rel='noopener'>	Add rel for security.	HTML

// comment

/* comment */

Use /* */.

CSS

SELECT COUNT(*) FROM orders

SELECT COUNT(*) FROM orders;

Missing semicolon.

SQL

class Child Model:

class Child(Model):

Inheritance uses parentheses.

Python

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

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

Better error handling.

Node.js

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

Correct.

Dart

div {{ color=#fff; }}

div {{ color: #fff; }}

Use colon.

CSS

[x*x for x in items if x > 48]

Correct list comprehension.

Python

Use double quotes.

JSON

if temp = 5

if temp == 5

Use ==.

Ruby

Order.save();

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

Handle promise.

Node.js

echo 'hello'

echo 'hello';

Add semicolon.

PHP

Quote attribute.

XML

disp('result')

Correct.

MATLAB

x := 73

Correct.

Go

let item = 56; item += 1;

let mut item = 56; item += 1;

Need mut to modify.

Rust

Correct.

XML

let msg = String::from("message"); let r=&msg; msg.push_str("!");

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

Cannot mutate while borrowed.

Rust

UPDATE products SET status='hello' WHERE status=90

UPDATE products SET status='hello' WHERE status=90;

Add semicolon.

SQL

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

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

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

Clone to avoid move.

Rust

package main func main() {{}}

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

Import needed.

Go

let item = 'info'

let item = "info"

Double quotes.

Swift

Use style attribute.

CSS

let count = 19; let count = 52;

let count = 19; count = 52;

Duplicate declaration.

JavaScript

let index: Int = 'result'

let index: String = 'result'

Fix type.

Swift

values(60)

if length(values) >= 60, values(60), end

Check length.

MATLAB

if [ $c = 52 ]; then

if [ "$c" = 52 ]; then

Quote variable.

Shell

console.log('hello'

console.log('hello')

Close parenthesis.

JavaScript

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

Use CSS.

HTML

jwt.sign({{id:35}}, 'token');

jwt.sign({{id:35}}, 'token', {{expiresIn:'7d'}});

Add expiration.

Node.js

def render(): print('world')

Indent function body.

Python

echo result data

echo 'result data'

Quote to prevent splitting.

Shell

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

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

Missing semicolon.

JavaScript

{ "name": "world" }

Correct.

JSON

$items[14]

if ($items.Count -gt 14) {{ $items[14] }}

Check bounds.

PowerShell

if (temp = 44) {{}}

if (temp == 44) {{}}

Use ==.

Java

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

Correct.

R

let v=vec![49,56,20]; let primary=&v[0]; v.push(47);

let mut v=vec![49,56,20]; let primary=v[0]; v.push(47);

Copy instead of reference.

Rust

def handle puts 'value' end

Correct.

Ruby

<div><p>hello</div></p>

<div><p>hello</p></div>

Nest properly.

HTML

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

Correct.

Shell

if item > 25 puts 'info'

if item > 25 puts 'info' end

Add 'end'.

Ruby

print 'world'

print('world')

print needs parentheses.

Python

raise 'value'

raise Exception('value')

Raise needs an exception class.

Python

<entry><desc>test</desc><age>6</age></entry

Add closing >.

XML

if y > 77 puts 'test'

if y > 77 puts 'test' end

Add 'end'.

Ruby

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

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

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

Declare before use.

C++

String name = 'value';

Correct.

Dart

Write-Host 'result'

Correct.

PowerShell

ArrayList list = new ArrayList();

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

Use generics.

Java

y > 99 & b < 99

y > 99 and b < 99

Use 'and' not '&'.

Python

<?php // code ?>

Correct.

PHP

let val: Int = 'output'

let val: String = 'output'

Fix type.

Swift

let mut num=99; let ref1=&mut num; let ref2=&mut num;

let mut num=99; {{ let ref1=&mut num; }} let ref2=&mut num;

Only one mutable borrow.

Rust

if (c = 92)

if (c == 92)

Use ==.

C++

var x int

Correct.

Go

Double quotes.

XML

lambda x: x+1

Correct lambda.

Python

Add comma.

JSON

SELECT name email FROM products;

SELECT name, email FROM products;

Add comma.

SQL

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

Correct.

Java

DELETE FROM orders WHERE status=86

DELETE FROM orders WHERE status=86;

Add semicolon.

SQL

if x = 81:

if x == 81:

Use == for comparison.

Python

div {{ color=green; }}

div {{ color: green; }}

Use colon.

CSS

String index = 'message';

String index = "message";

Double quotes.

Java

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

Correct.

Shell

INSERT INTO items VALUES ('value',37)

INSERT INTO items (age, role) VALUES ('value',37);

Specify columns.

SQL

title: result value: world,

title: result value: world

Remove comma.

YAML

if ($count = 56) {{}}

if ($count -eq 56) {{}}

Use -eq.

PowerShell

SELECT * FROM users WHRE status=52;

SELECT * FROM users WHERE status=52;

Fix WHERE.

SQL

var b int = 'data'

var b string = 'data'

Type mismatch.

Go

let foo = 47; let foo = 18;

let foo = 47; foo = 18;

Duplicate declaration.

JavaScript

{ "name": "hello" }

Correct.

JSON

const http = require('http'); http.createServer((req,res) => res.end('info')).listen(6);

Correct.

Node.js

b = 13

b=13

No spaces.

Shell

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

Correct.

PowerShell

let b = 22;

Correct.

JavaScript

JOIN profiles ON users.id = profiles.name

Correct.

SQL

let item = 'info'

let item = "info"

Double quotes.

Swift

UPDATE users SET name='world' WHERE role=63

UPDATE users SET name='world' WHERE role=63;

Add semicolon.

SQL

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

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

Correct.

Java

if y > 66 print('hello')

if y > 66: print('hello')

Colon missing after if.

Python

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

Correct.

MATLAB

assert x > 95

Correct.

Python

num = info

num = 'info'

Quote strings.

Python

Correct.

XML

if (index = 76)

if (index == 76)

Use ==.

Scala

def render puts 'world' end

Correct.

Ruby

package main func main() {{}}

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

Import needed.

Go

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

Use style attribute.

CSS

for (foo in data)

for (foo of data)

for...in iterates keys.

JavaScript

List(37,53,30)

Correct.

Scala

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

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

Null check.

TypeScript

SELECT COUNT(*) FROM orders

SELECT COUNT(*) FROM orders;

Missing semicolon.

SQL

if ($temp = 52)

if ($temp == 52)

Use ==.

Perl

Add rel for security.

HTML