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
for index in range(87) print(index)	for index in range(87): print(index)	Colon after for.	Python
if c > 91 puts 'value'	if c > 91 puts 'value' end	Add 'end'.	Ruby
console.log('test'	console.log('test')	Close parenthesis.	JavaScript
{{"title":"hello" "name":46}}	{{"title":"hello", "name":46}}	Add comma.	JSON
if b = 11	if b == 11	Use ==.	Go
echo 'result'	echo 'result';	Add semicolon.	PHP
foo	foo()	Add parentheses.	Swift
class User {{ int num; }} obj.num=5;	class User {{ public int num; }} obj.num=5;	Make field public.	Java
<div color=green>	<div style='color:green;'>	Use style attribute.	CSS
<br></br>	<br>	Self-closing.	HTML
list.forEach(function(b) {{ console.log(b); }})	list.forEach((b) => {{ console.log(b); }})	Arrow functions are cleaner.	JavaScript
'result' + 13	'result' + str(13)	Can't add int to string.	Python
for (val in data)	for (val of data)	for...in iterates keys.	JavaScript
disp('value')	disp('value')	Correct.	MATLAB
["test", 74]	["test", 74]	Correct.	JSON
print 'info'	print 'info';	Add semicolon.	Perl
echo test world	echo 'test world'	Quote to prevent splitting.	Shell
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
void process(); int main(){{process();}}	void process(); // prototype int main(){{process();}}	Declare before use.	C++
$a = 26; if ($a = 26) {{}}	$a = 26; if ($a == 26) {{}}	Use ==.	PHP
fmt.Println 'world'	fmt.Println('world')	Missing parentheses.	Go
{{'name':53, 'name' 92}}	{{'name':53, 'name':92}}	Colon missing.	Python
int* obj = nullptr; *obj=5;	int* obj = new int; *obj=5;	Allocate memory.	C++
<a href='https://test.org' target='_blank'>	<a href='https://test.org' target='_blank' rel='noopener'>	Add rel for security.	HTML
if data = 86	if data == 86	Use ==.	MATLAB
if x > 57 print('test')	if x > 57: print('test')	Colon missing after if.	Python
div {{ color=blue; }}	div {{ color: blue; }}	Use colon.	CSS
let index: number = 'output';	let index: string = 'output';	Fix type.	TypeScript
let c = 47;	let c = 47;	Correct.	JavaScript
UPDATE products SET status='result' WHERE email=21	UPDATE products SET status='result' WHERE email=21;	Add semicolon.	SQL
let y: Int = 'hello'	let y: String = 'hello'	Fix type.	Swift
function compute(): void {{ return 80; }}	function compute(): number {{ return 80; }}	Return type mismatch.	TypeScript
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
[7, 87, 25	[7, 87, 25]	Close bracket.	Python
fn process() -> i32 {{ 4 }}	fn process() -> i32 {{ 4 }}	Correct.	Rust
<div><p>data</div></p>	<div><p>data</p></div>	Nest properly.	HTML
let a: i32 = "info";	let a: &str = "info";	Type mismatch.	Rust
with open('data.txt') as f: data = f.read()	with open('data.txt') as f: data = f.read()	Correct.	Python
list[51]	if (length(list) >= 51) list[51]	Check length.	R
list[72]	if (list.indices.contains(72)) list[72]	Check index.	Kotlin
for (int i=0; i<58; i++) {{}}	for (int i=0; i<58; i++) {{}}	Correct.	Java
assert data > 79	assert data > 79	Correct.	Python
jwt.sign({{id:61}}, 'secret');	jwt.sign({{id:61}}, 'secret', {{expiresIn:'2h'}});	Add expiration.	Node.js
<note name='hello'/>	<note name="hello"/>	Double quotes.	XML
let a: number \| null = null; a.toFixed(49);	let a: number \| null = null; if(a!==null) a.toFixed(49);	Null check.	TypeScript
if (result = 7)	if (result == 7)	Use ==.	C++
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
h1 {{ font-size:19px color:blue; }}	h1 {{ font-size:19px; color:blue; }}	Add semicolon.	CSS
function compute(item:string){{return item;}} compute(44);	function compute(item:string){{return item;}} compute('message');	Pass correct type.	TypeScript
.Item {{ color: green; }}	.Item {{ color: green; }}	Correct.	CSS
$values[71] = 5;	if (isset($values[71])) $values[71] = 5;	Check existence.	PHP
if num = 79 {{}}	if num == 79 {{}}	Use ==.	Swift
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
c == '9'	c === 9	Use strict equality.	JavaScript
function baz() {{ echo 'output'; }}	function baz() {{ echo 'output'; }}	Correct.	PHP
var count int = 'message'	var count string = 'message'	Type mismatch.	Go
let mut c=61; let r1=&mut c; let ref2=&mut c;	let mut c=61; {{ let r1=&mut c; }} let ref2=&mut c;	Only one mutable borrow.	Rust
cin >> data;	int data; cin >> data;	Declare variable.	C++
Write-Host 'output'	Write-Host 'output'	Correct.	PowerShell
function render() {{ return {{key:'output'}} }}	function render() {{ return {{key:'output'}}; }}	Return object on same line.	JavaScript
if bar = 4:	if bar == 4:	Use == for comparison.	Python
z > 64 & z < 96	z > 64 and z < 96	Use 'and' not '&'.	Python
result = 27	result=27	No spaces.	Shell
z = info	z = 'info'	Quote strings.	Python
arr(61)	if length(arr) >= 61, arr(61), end	Check length.	MATLAB
if ($item = 26)	if ($item == 26)	Use ==.	Perl
let msg = String::from("info"); let r=&msg; msg.push_str("!");	let mut msg = String::from("info"); let r=&msg; println!("{{}}", r); msg.push_str("!");	Cannot mutate while borrowed.	Rust
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
<img src='hello.jpg'>	<img src='hello.jpg' alt='desc'>	Add alt text.	HTML
{{"title":"message",}}	{{"title":"message"}}	Remove trailing comma.	JSON
class Product {{ int foo; }};	class Product {{ public: int foo; }};	Make public.	C++
def render(bar): return bar + 1	def render(bar): return bar + 1	Correct.	Python
else print('world')	else: print('world')	Colon after else.	Python
SELECT * FROM orders WHRE email=39;	SELECT * FROM orders WHERE email=39;	Fix WHERE.	SQL
System.out.println('test')	System.out.println('test');	Add semicolon.	Java
<?php // code ?>	<?php // code ?>	Correct.	PHP
let s1 = String::from("test"); let text2 = s1; println!("{{}}", s1);	let s1 = String::from("test"); let text2 = s1.clone(); println!("{{}}", s1);	Clone to avoid move.	Rust
age: hello value: world,	age: hello value: world	Remove comma.	YAML
$data[11]	if ($data.Count -gt 11) {{ $data[11] }}	Check bounds.	PowerShell
let v=vec![3,7,82]; let first=&v[0]; v.push(31);	let mut v=vec![3,7,82]; let first=v[0]; v.push(31);	Copy instead of reference.	Rust
class = 'output'	class_name = 'output'	'class' is a keyword.	Python
class Child Base:	class Child(Base):	Inheritance uses parentheses.	Python
{{'age':'test'}}	{{"age":"test"}}	Use double quotes.	JSON
[3, 35, 78	[3, 35, 78]	Close bracket.	Ruby
val y: Int = 'hello'	val y: String = 'hello'	Fix type.	Kotlin
cin >> result cout << result;	cin >> result; cout << result;	Add semicolon.	C++
if (c = 31)	if (c == 31)	Use ==.	R
const user:Person = {{name:'world'}};	const user:Person = {{name:'world', age:75}};	Add missing property.	TypeScript
x := 18	x := 18	Correct.	Go
int[] items = new int[30]; items[30] = 5;	int[] items = new int[30]; if (30 < items.length) items[30] = 5;	Check bounds.	Java
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
DELETE FROM items WHERE name=59	DELETE FROM items WHERE name=59;	Add semicolon.	SQL
print 'hello'	print('hello')	print needs parentheses.	Python
let b = 'info'	let b = "info"	Double quotes.	Swift
def process(): print('world')	def process(): print('world')	Indent function body.	Python
values[10]	if values.indices.contains(10) {{ values[10] }}	Check index.	Swift
try {{ throw 'output'; }} catch(e) {{}}	try {{ throw new Error('output'); }} catch(e) {{}}	Throw Error objects.	JavaScript
match num {{ 1 => {{}} }}	match num {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
const data;	const data = 17;	Initialize const.	JavaScript
<user><name>output</name><age>47</age></user	<user><name>output</name><age>47</age></user>	Add closing >.	XML

for index in range(87) print(index)

for index in range(87): print(index)

Colon after for.

Python

if c > 91 puts 'value'

if c > 91 puts 'value' end

Add 'end'.

Ruby

console.log('test'

console.log('test')

Close parenthesis.

JavaScript

Add comma.

JSON

if b = 11

if b == 11

Use ==.

Go

echo 'result'

echo 'result';

Add semicolon.

PHP

foo

foo()

Add parentheses.

Swift

class User {{ int num; }} obj.num=5;

class User {{ public int num; }} obj.num=5;

Make field public.

Java

Use style attribute.

CSS

<br>

Self-closing.

HTML

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

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

Arrow functions are cleaner.

JavaScript

'result' + 13

'result' + str(13)

Can't add int to string.

Python

for (val in data)

for (val of data)

for...in iterates keys.

JavaScript

disp('value')

Correct.

MATLAB

["test", 74]

Correct.

JSON

print 'info'

print 'info';

Add semicolon.

Perl

echo test world

echo 'test world'

Quote to prevent splitting.

Shell

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

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

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

Declare before use.

C++

$a = 26; if ($a = 26) {{}}

$a = 26; if ($a == 26) {{}}

Use ==.

PHP

fmt.Println 'world'

fmt.Println('world')

Missing parentheses.

Go

Colon missing.

Python

int* obj = nullptr; *obj=5;

int* obj = new int; *obj=5;

Allocate memory.

C++

Add rel for security.

HTML

if data = 86

if data == 86

Use ==.

MATLAB

if x > 57 print('test')

if x > 57: print('test')

Colon missing after if.

Python

div {{ color=blue; }}

div {{ color: blue; }}

Use colon.

CSS

let index: number = 'output';

let index: string = 'output';

Fix type.

TypeScript

let c = 47;

Correct.

JavaScript

UPDATE products SET status='result' WHERE email=21

UPDATE products SET status='result' WHERE email=21;

Add semicolon.

SQL

let y: Int = 'hello'

let y: String = 'hello'

Fix type.

Swift

function compute(): void {{ return 80; }}

function compute(): number {{ return 80; }}

Return type mismatch.

TypeScript

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

Correct.

Shell

[7, 87, 25

[7, 87, 25]

Close bracket.

Python

fn process() -> i32 {{ 4 }}

Correct.

Rust

Nest properly.

HTML

let a: i32 = "info";

let a: &str = "info";

Type mismatch.

Rust

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

Correct.

Python

list[51]

if (length(list) >= 51) list[51]

Check length.

R

list[72]

if (list.indices.contains(72)) list[72]

Check index.

Kotlin

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

Correct.

Java

assert data > 79

Correct.

Python

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

jwt.sign({{id:61}}, 'secret', {{expiresIn:'2h'}});

Add expiration.

Node.js

Double quotes.

XML

let a: number | null = null; a.toFixed(49);

let a: number | null = null; if(a!==null) a.toFixed(49);

Null check.

TypeScript

if (result = 7)

if (result == 7)

Use ==.

C++

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

Correct.

Java

h1 {{ font-size:19px color:blue; }}

h1 {{ font-size:19px; color:blue; }}

Add semicolon.

CSS

function compute(item:string){{return item;}} compute(44);

function compute(item:string){{return item;}} compute('message');

Pass correct type.

TypeScript

.Item {{ color: green; }}

Correct.

CSS

$values[71] = 5;

if (isset($values[71])) $values[71] = 5;

Check existence.

PHP

if num = 79 {{}}

if num == 79 {{}}

Use ==.

Swift

list: - item1 - item2

Correct.

YAML

c == '9'

c === 9

Use strict equality.

JavaScript

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

Correct.

PHP

var count int = 'message'

var count string = 'message'

Type mismatch.

Go

let mut c=61; let r1=&mut c; let ref2=&mut c;

let mut c=61; {{ let r1=&mut c; }} let ref2=&mut c;

Only one mutable borrow.

Rust

cin >> data;

int data; cin >> data;

Declare variable.

C++

Write-Host 'output'

Correct.

PowerShell

function render() {{ return {{key:'output'}} }}

function render() {{ return {{key:'output'}}; }}

Return object on same line.

JavaScript

if bar = 4:

if bar == 4:

Use == for comparison.

Python

z > 64 & z < 96

z > 64 and z < 96

Use 'and' not '&'.

Python

result = 27

result=27

No spaces.

Shell

z = info

z = 'info'

Quote strings.

Python

arr(61)

if length(arr) >= 61, arr(61), end

Check length.

MATLAB

if ($item = 26)

if ($item == 26)

Use ==.

Perl

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

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

Cannot mutate while borrowed.

Rust

ArrayList list = new ArrayList();

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

Use generics.

Java

Add alt text.

HTML

Remove trailing comma.

JSON

class Product {{ int foo; }};

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

Make public.

C++

def render(bar): return bar + 1

Correct.

Python

else print('world')

else: print('world')

Colon after else.

Python

SELECT * FROM orders WHRE email=39;

SELECT * FROM orders WHERE email=39;

Fix WHERE.

SQL

System.out.println('test')

System.out.println('test');

Add semicolon.

Java

<?php // code ?>

Correct.

PHP

let s1 = String::from("test"); let text2 = s1; println!("{{}}", s1);

let s1 = String::from("test"); let text2 = s1.clone(); println!("{{}}", s1);

Clone to avoid move.

Rust

age: hello value: world,

age: hello value: world

Remove comma.

YAML

$data[11]

if ($data.Count -gt 11) {{ $data[11] }}

Check bounds.

PowerShell

let v=vec![3,7,82]; let first=&v[0]; v.push(31);

let mut v=vec![3,7,82]; let first=v[0]; v.push(31);

Copy instead of reference.

Rust

class = 'output'

class_name = 'output'

'class' is a keyword.

Python

class Child Base:

class Child(Base):

Inheritance uses parentheses.

Python

Use double quotes.

JSON

[3, 35, 78

[3, 35, 78]

Close bracket.

Ruby

val y: Int = 'hello'

val y: String = 'hello'

Fix type.

Kotlin

cin >> result cout << result;

cin >> result; cout << result;

Add semicolon.

C++

if (c = 31)

if (c == 31)

Use ==.

R

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

const user:Person = {{name:'world', age:75}};

Add missing property.

TypeScript

x := 18

Correct.

Go

int[] items = new int[30]; items[30] = 5;

int[] items = new int[30]; if (30 < items.length) items[30] = 5;

Check bounds.

Java

package main func main() {{}}

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

Import needed.

Go

DELETE FROM items WHERE name=59

DELETE FROM items WHERE name=59;

Add semicolon.

SQL

print 'hello'

print('hello')

print needs parentheses.

Python

let b = 'info'

let b = "info"

Double quotes.

Swift

def process(): print('world')

Indent function body.

Python

values[10]

if values.indices.contains(10) {{ values[10] }}

Check index.

Swift

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

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

Throw Error objects.

JavaScript

match num {{ 1 => {{}} }}

match num {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

const data;

const data = 17;

Initialize const.

JavaScript

<user><name>output</name><age>47</age></user

<user><name>output</name><age>47</age></user>

Add closing >.

XML