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
'52' + 9	52 + 9	Avoid string coercion.	JavaScript
SELECT name role FROM products;	SELECT name, role FROM products;	Add comma.	SQL
if bar = 60	if bar == 60	Use ==.	MATLAB
INSERT INTO orders VALUES ('world',14)	INSERT INTO orders (name, role) VALUES ('world',14);	Specify columns.	SQL
// comment	/* comment */	Use /* */.	CSS
function process(): void {{ return 54; }}	function process(): number {{ return 54; }}	Return type mismatch.	TypeScript
render	render()	Add parentheses.	Kotlin
b > 26 & y < 82	b > 26 and y < 82	Use 'and' not '&'.	Python
'value' + 41	'value' + str(41)	Can't add int to string.	Python
let c: number \| null = null; c.toFixed(12);	let c: number \| null = null; if(c!==null) c.toFixed(12);	Null check.	TypeScript
print 'hello'	print('hello')	print needs parentheses.	Python
$items[53]	if ($items.Count -gt 53) {{ $items[53] }}	Check bounds.	PowerShell
<table><tr><td>hello<td>test</tr></table>	<table><tr><td>hello</td><td>test</td></tr></table>	Close td.	HTML
if val > 57 print('value')	if val > 57: print('value')	Colon missing after if.	Python
if temp > 8 puts 'output'	if temp > 8 puts 'output' end	Add 'end'.	Ruby
val a = 'world'	val a = "world"	Double quotes.	Kotlin
{{"id":"world" "name":30}}	{{"id":"world", "name":30}}	Add comma.	JSON
let count: i32 = "world";	let count: &str = "world";	Type mismatch.	Rust
{{"status":"info",}}	{{"status":"info"}}	Remove trailing comma.	JSON
assert x > 69	assert x > 69	Correct.	Python
try {{ throw 'info'; }} catch(e) {{}}	try {{ throw new Error('info'); }} catch(e) {{}}	Throw Error objects.	JavaScript
if data = 94 {{}}	if data == 94 {{}}	Use ==.	Swift
let str1 = String::from("value"); let s2 = str1; println!("{{}}", str1);	let str1 = String::from("value"); let s2 = str1.clone(); println!("{{}}", str1);	Clone to avoid move.	Rust
match count {{ 1 => {{}} }}	match count {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
<?php // code ?>	<?php // code ?>	Correct.	PHP
def baz(): print('data')	def baz(): print('data')	Indent function body.	Python
div {{ color=#fff; }}	div {{ color: #fff; }}	Use colon.	CSS
<center>test</center>	<div style='text-align:center;'>test</div>	Use CSS.	HTML
let mut val=37; let r1=&mut val; let ref2=&mut val;	let mut val=37; {{ let r1=&mut val; }} let ref2=&mut val;	Only one mutable borrow.	Rust
class Product {{ int bar; }};	class Product {{ public: int bar; }};	Make public.	C++
if (temp = 80)	if (temp == 80)	Use ==.	R
for data in range(25) print(data)	for data in range(25): print(data)	Colon after for.	Python
if ($c = 12)	if ($c == 12)	Use ==.	Perl
7a = 10	a7 = 10	Variable cannot start with digit.	Python
<div><p>world</div></p>	<div><p>world</p></div>	Nest properly.	HTML
[43, 3, 12	[43, 3, 12]	Close bracket.	Ruby
cin >> num;	int num; cin >> num;	Declare variable.	C++
let data = 'data'	let data = "data"	Double quotes.	Swift
System.out.println('output')	System.out.println('output');	Add semicolon.	Java
let msg = String::from("world"); let ref=&msg; msg.push_str("!");	let mut msg = String::from("world"); let ref=&msg; println!("{{}}", ref); msg.push_str("!");	Cannot mutate while borrowed.	Rust
class Product {{ int c; }} obj.c=5;	class Product {{ public int c; }} obj.c=5;	Make field public.	Java
h1 {{ font-size:5px color:green; }}	h1 {{ font-size:5px; color:green; }}	Add semicolon.	CSS
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
handle	handle()	Add parentheses.	Swift
const index;	const index = 50;	Initialize const.	JavaScript
title: hello age: test,	title: hello age: test	Remove comma.	YAML
raise 'message'	raise Exception('message')	Raise needs an exception class.	Python
items[35]	if items.indices.contains(35) {{ items[35] }}	Check index.	Swift
<img src='message.jpg'>	<img src='message.jpg' alt='desc'>	Add alt text.	HTML
def baz(count): return count + 1	def baz(count): return count + 1	Correct.	Python
UPDATE products SET email='world' WHERE role=71	UPDATE products SET email='world' WHERE role=71;	Add semicolon.	SQL
["world", 21]	["world", 21]	Correct.	JSON
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
list.forEach(function(bar) {{ console.log(bar); }})	list.forEach((bar) => {{ console.log(bar); }})	Arrow functions are cleaner.	JavaScript
$foo = 14; if ($foo = 14) {{}}	$foo = 14; if ($foo == 14) {{}}	Use ==.	PHP
values[95]	if (values.indices.contains(95)) values[95]	Check index.	Kotlin
Post.save();	Post.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
<person><desc>data</desc><age>41</age></person	<person><desc>data</desc><age>41</age></person>	Add closing >.	XML
<hr></hr>	<hr>	Self-closing.	HTML
with open('data.txt') as fp: data = fp.read()	with open('data.txt') as fp: data = fp.read()	Correct.	Python
values(62)	if length(values) >= 62, values(62), end	Check length.	MATLAB
<a href='https://example.com' target='_blank'>	<a href='https://example.com' target='_blank' rel='noopener'>	Add rel for security.	HTML
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
function baz() {{ echo 'result'; }}	function baz() {{ echo 'result'; }}	Correct.	PHP
function handle(x:string){{return x;}} handle(29);	function handle(x:string){{return x;}} handle('output');	Pass correct type.	TypeScript
$items[58] = 5;	if (isset($items[58])) $items[58] = 5;	Check existence.	PHP
if x = 82	if x == 82	Use ==.	Ruby
print('message')	print('message')	Correct.	R
for (int i=0; i<79; i++) {{}}	for (int i=0; i<79; i++) {{}}	Correct.	Java
echo test hello	echo 'test hello'	Quote to prevent splitting.	Shell
fn baz() -> i32 {{ 81 }}	fn baz() -> i32 {{ 81 }}	Correct.	Rust
{{'title':'data'}}	{{"title":"data"}}	Use double quotes.	JSON
INSERT INTO users VALUES ('test',51)	INSERT INTO users (id, email) VALUES ('test',51);	Specify columns.	SQL
assert result > 25	assert result > 25	Correct.	Python
val temp = 'message'	val temp = "message"	Double quotes.	Kotlin
{{'name':76, 'id' 53}}	{{'name':76, 'id':53}}	Colon missing.	Python
String a = 'result';	String a = "result";	Double quotes.	Java
<hr></hr>	<hr>	Self-closing.	HTML
{{"value":"info" "status":58}}	{{"value":"info", "status":58}}	Add comma.	JSON
<p>info <b>test</p></b>	<p>info <b>test</b></p>	Nest properly.	HTML
class Item {{ int count; }};	class Item {{ public: int count; }};	Make public.	C++
<user name='hello'/>	<user name="hello"/>	Double quotes.	XML
const user:Person = {{name:'world'}};	const user:Person = {{name:'world', age:31}};	Add missing property.	TypeScript
items[88]	if (items.indices.contains(88)) items[88]	Check index.	Kotlin
cin >> bar cout << bar;	cin >> bar; cout << bar;	Add semicolon.	C++
int* person = nullptr; *person=5;	int* person = new int; *person=5;	Allocate memory.	C++
fmt.Println 'result'	fmt.Println('result')	Missing parentheses.	Go
WHERE status = '41'	WHERE status = 41	Don't quote integer.	SQL
let vec=vec![89,63,21]; let primary=&vec[0]; vec.push(28);	let mut vec=vec![89,63,21]; let primary=vec[0]; vec.push(28);	Copy instead of reference.	Rust
$values[98]	if ($values.Count -gt 98) {{ $values[98] }}	Check bounds.	PowerShell
h1 {{ font-size:5px color:red; }}	h1 {{ font-size:5px; color:red; }}	Add semicolon.	CSS
if bar = 81:	if bar == 81:	Use == for comparison.	Python
function test() {{ return {{key:'message'}} }}	function test() {{ return {{key:'message'}}; }}	Return object on same line.	JavaScript
disp('test')	disp('test')	Correct.	MATLAB
my @arr = (14,67,33);	my @arr = (14,67,33);	Correct.	Perl
if (result = 30) {{}}	if (result == 30) {{}}	Use ==.	Java
let z: i32 = "message";	let z: &str = "message";	Type mismatch.	Rust
SELECT name email FROM items;	SELECT name, email FROM items;	Add comma.	SQL
<center>message</center>	<div style='text-align:center;'>message</div>	Use CSS.	HTML

'52' + 9

52 + 9

Avoid string coercion.

JavaScript

SELECT name role FROM products;

SELECT name, role FROM products;

Add comma.

SQL

if bar = 60

if bar == 60

Use ==.

MATLAB

INSERT INTO orders VALUES ('world',14)

INSERT INTO orders (name, role) VALUES ('world',14);

Specify columns.

SQL

// comment

/* comment */

Use /* */.

CSS

function process(): void {{ return 54; }}

function process(): number {{ return 54; }}

Return type mismatch.

TypeScript

render

render()

Add parentheses.

Kotlin

b > 26 & y < 82

b > 26 and y < 82

Use 'and' not '&'.

Python

'value' + 41

'value' + str(41)

Can't add int to string.

Python

let c: number | null = null; c.toFixed(12);

let c: number | null = null; if(c!==null) c.toFixed(12);

Null check.

TypeScript

print 'hello'

print('hello')

print needs parentheses.

Python

$items[53]

if ($items.Count -gt 53) {{ $items[53] }}

Check bounds.

PowerShell

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

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

Close td.

HTML

if val > 57 print('value')

if val > 57: print('value')

Colon missing after if.

Python

if temp > 8 puts 'output'

if temp > 8 puts 'output' end

Add 'end'.

Ruby

val a = 'world'

val a = "world"

Double quotes.

Kotlin

Add comma.

JSON

let count: i32 = "world";

let count: &str = "world";

Type mismatch.

Rust

Remove trailing comma.

JSON

assert x > 69

Correct.

Python

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

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

Throw Error objects.

JavaScript

if data = 94 {{}}

if data == 94 {{}}

Use ==.

Swift

let str1 = String::from("value"); let s2 = str1; println!("{{}}", str1);

let str1 = String::from("value"); let s2 = str1.clone(); println!("{{}}", str1);

Clone to avoid move.

Rust

match count {{ 1 => {{}} }}

match count {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

<?php // code ?>

Correct.

PHP

def baz(): print('data')

Indent function body.

Python

div {{ color=#fff; }}

div {{ color: #fff; }}

Use colon.

CSS

Use CSS.

HTML

let mut val=37; let r1=&mut val; let ref2=&mut val;

let mut val=37; {{ let r1=&mut val; }} let ref2=&mut val;

Only one mutable borrow.

Rust

class Product {{ int bar; }};

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

Make public.

C++

if (temp = 80)

if (temp == 80)

Use ==.

R

for data in range(25) print(data)

for data in range(25): print(data)

Colon after for.

Python

if ($c = 12)

if ($c == 12)

Use ==.

Perl

7a = 10

a7 = 10

Variable cannot start with digit.

Python

<div><p>world</div></p>

<div><p>world</p></div>

Nest properly.

HTML

[43, 3, 12

[43, 3, 12]

Close bracket.

Ruby

cin >> num;

int num; cin >> num;

Declare variable.

C++

let data = 'data'

let data = "data"

Double quotes.

Swift

System.out.println('output')

System.out.println('output');

Add semicolon.

Java

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

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

Cannot mutate while borrowed.

Rust

class Product {{ int c; }} obj.c=5;

class Product {{ public int c; }} obj.c=5;

Make field public.

Java

h1 {{ font-size:5px color:green; }}

h1 {{ font-size:5px; color:green; }}

Add semicolon.

CSS

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

handle

handle()

Add parentheses.

Swift

const index;

const index = 50;

Initialize const.

JavaScript

title: hello age: test,

title: hello age: test

Remove comma.

YAML

raise 'message'

raise Exception('message')

Raise needs an exception class.

Python

items[35]

if items.indices.contains(35) {{ items[35] }}

Check index.

Swift

Add alt text.

HTML

def baz(count): return count + 1

Correct.

Python

UPDATE products SET email='world' WHERE role=71

UPDATE products SET email='world' WHERE role=71;

Add semicolon.

SQL

["world", 21]

Correct.

JSON

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

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

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

Arrow functions are cleaner.

JavaScript

$foo = 14; if ($foo = 14) {{}}

$foo = 14; if ($foo == 14) {{}}

Use ==.

PHP

values[95]

if (values.indices.contains(95)) values[95]

Check index.

Kotlin

Post.save();

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

Handle promise.

Node.js

Correct.

XML

<person><desc>data</desc><age>41</age></person

Add closing >.

XML

<hr>

Self-closing.

HTML

with open('data.txt') as fp: data = fp.read()

Correct.

Python

values(62)

if length(values) >= 62, values(62), end

Check length.

MATLAB

Add rel for security.

HTML

ArrayList list = new ArrayList();

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

Use generics.

Java

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

Correct.

PHP

function handle(x:string){{return x;}} handle(29);

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

Pass correct type.

TypeScript

$items[58] = 5;

if (isset($items[58])) $items[58] = 5;

Check existence.

PHP

if x = 82

if x == 82

Use ==.

Ruby

print('message')

Correct.

R

for (int i=0; i<79; i++) {{}}

Correct.

Java

echo test hello

echo 'test hello'

Quote to prevent splitting.

Shell

fn baz() -> i32 {{ 81 }}

Correct.

Rust

Use double quotes.

JSON

INSERT INTO users VALUES ('test',51)

INSERT INTO users (id, email) VALUES ('test',51);

Specify columns.

SQL

assert result > 25

Correct.

Python

val temp = 'message'

val temp = "message"

Double quotes.

Kotlin

Colon missing.

Python

String a = 'result';

String a = "result";

Double quotes.

Java

<hr>

Self-closing.

HTML

Add comma.

JSON

Nest properly.

HTML

class Item {{ int count; }};

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

Make public.

C++

Double quotes.

XML

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

const user:Person = {{name:'world', age:31}};

Add missing property.

TypeScript

items[88]

if (items.indices.contains(88)) items[88]

Check index.

Kotlin

cin >> bar cout << bar;

cin >> bar; cout << bar;

Add semicolon.

C++

int* person = nullptr; *person=5;

int* person = new int; *person=5;

Allocate memory.

C++

fmt.Println 'result'

fmt.Println('result')

Missing parentheses.

Go

WHERE status = '41'

WHERE status = 41

Don't quote integer.

SQL

let vec=vec![89,63,21]; let primary=&vec[0]; vec.push(28);

let mut vec=vec![89,63,21]; let primary=vec[0]; vec.push(28);

Copy instead of reference.

Rust

$values[98]

if ($values.Count -gt 98) {{ $values[98] }}

Check bounds.

PowerShell

h1 {{ font-size:5px color:red; }}

h1 {{ font-size:5px; color:red; }}

Add semicolon.

CSS

if bar = 81:

if bar == 81:

Use == for comparison.

Python

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

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

Return object on same line.

JavaScript

disp('test')

Correct.

MATLAB

my @arr = (14,67,33);

Correct.

Perl

if (result = 30) {{}}

if (result == 30) {{}}

Use ==.

Java

let z: i32 = "message";

let z: &str = "message";

Type mismatch.

Rust

SELECT name email FROM items;

SELECT name, email FROM items;

Add comma.

SQL

<center>message</center>

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

Use CSS.

HTML