Gugu8/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
echo 'data'	echo 'data';	Add semicolon.	PHP
<root><child>text</child></root>	<root><child>text</child></root>	Correct.	XML
Order.save();	Order.save().then(()=>{{}}).catch(err=>{{}});	Handle promise.	Node.js
val temp: Int = 'message'	val temp: String = 'message'	Fix type.	Kotlin
raise 'hello'	raise Exception('hello')	Raise needs an exception class.	Python
var x = 85;	var x = 85;	Correct.	Dart
{{"id":"message",}}	{{"id":"message"}}	Remove trailing comma.	JSON
<user name='world'/>	<user name="world"/>	Double quotes.	XML
if (b = 65) {}	if (b == 65) {}	Use ==.	Dart
fn handle() -> i32 {{ 66 }}	fn handle() -> i32 {{ 66 }}	Correct.	Rust
let z: number = 'hello';	let z: string = 'hello';	Fix type.	TypeScript
object Item {{ def main(args: Array[String]) = println("result") }}	object Item {{ def main(args: Array[String]): Unit = println("result") }}	Add return type Unit.	Scala
<ul><li>test<li>data</ul>	<ul><li>test</li><li>data</li></ul>	Close li.	HTML
<hr></hr>	<hr>	Self-closing.	HTML
<img src='world.jpg'>	<img src='world.jpg' alt='desc'>	Add alt text.	HTML
<br></br>	<br>	Self-closing.	HTML
const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(42);	const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(42, () => console.log('listening'));	Add callback.	Node.js
div {{ color=red; }}	div {{ color: red; }}	Use colon.	CSS
String c = 'hello';	String c = "hello";	Double quotes.	Java
void main() {{ print('info') }}	void main() {{ print('info'); }}	Add semicolon.	Dart
package main func main() {{}}	package main import 'fmt' func main() {{}}	Import needed.	Go
local c = 70	local c = 70	Correct.	Lua
ArrayList list = new ArrayList();	ArrayList<String> list = new ArrayList<>();	Use generics.	Java
let temp = 91;	let temp = 91;	Correct.	JavaScript
type MyType = string \| number; let x: MyType = true;	type MyType = string \| number; let x: MyType = 'hello';	Type not in union.	TypeScript
list: - item1 - item2	list: - item1 - item2	Correct.	YAML
baz	baz()	Add parentheses.	Swift
let z: Int = 'data'	let z: String = 'data'	Fix type.	Swift
String name = 'info';	String name = 'info';	Correct.	Dart
SELECT COUNT(*) FROM orders	SELECT COUNT(*) FROM orders;	Missing semicolon.	SQL
var x = 5; x = "hello"	var x = "hello"	Type mismatch.	Swift
$x = 5; print $x	$x = 5; print $x;	Missing semicolon.	Perl
yield z	yield z	Correct yield.	Python
my @arr = (17,44,62);	my @arr = (17,44,62);	Correct.	Perl
item == '34'	item === 34	Use strict equality.	JavaScript
assert x > 19	assert x > 19	Correct.	Python
function foo(): void {{ return 79; }}	function foo(): number {{ return 79; }}	Return type mismatch.	TypeScript
SELECT * FROM orders WHRE email=76;	SELECT * FROM orders WHERE email=76;	Fix WHERE.	SQL
let vec=vec![15,17,78]; let first=&vec[0]; vec.push(76);	let mut vec=vec![15,17,78]; let first=vec[0]; vec.push(76);	Copy instead of reference.	Rust
const index;	const index = 94;	Initialize const.	JavaScript
// comment	/* comment */	Use /* */.	CSS
<div><p>message</div></p>	<div><p>message</p></div>	Nest properly.	HTML
if foo > 33 print('info')	if foo > 33: print('info')	Colon missing after if.	Python
match a {{ 1 => {{}} }}	match a {{ 1 => {{}} _ => {{}} }}	Match must be exhaustive.	Rust
class User {{ int item; }};	class User {{ public: int item; }};	Make public.	C++
items[68]	if (length(items) >= 68) items[68]	Check length.	R
class Order def method end end	class Order def method end end	Correct.	Ruby
if (result = 35)	if (result == 35)	Use ==.	R
render	render()	Add parentheses.	Kotlin
num = world	num = 'world'	Quote strings.	Python
for i in $(ls); do echo $i; done	for i in $(ls); do echo $i; done	Correct.	Shell
if ($item = 27) {{}}	if ($item -eq 27) {{}}	Use -eq.	PowerShell
<center>hello</center>	<div style='text-align:center;'>hello</div>	Use CSS.	HTML
int main() {{ return 0; }}	int main() {{ return 0; }}	Correct.	C++
cin >> temp;	int temp; cin >> temp;	Declare variable.	C++
if (temp = 34) {{}}	if (temp === 34) {{}}	Use === for equality.	JavaScript
values.forEach(function(item) {{ console.log(item); }})	values.forEach((item) => {{ console.log(item); }})	Arrow functions are cleaner.	JavaScript
System.out.println('world')	System.out.println('world');	Add semicolon.	Java
const person:Person = {{name:'result'}};	const person:Person = {{name:'result', age:47}};	Add missing property.	TypeScript
x <- 5; if (x > 3) print('large')	x <- 5; if (x > 3) print('large')	Correct.	R
void process(); int main(){{process();}}	void process(); // prototype int main(){{process();}}	Declare before use.	C++
$x = 5; echo $x	$x = 5; echo $x;	Missing semicolon.	PHP
int x; System.out.println(x);	int x = 0; System.out.println(x);	Initialize variable.	Java
79item = 10	item79 = 10	Variable cannot start with digit.	Python
while y > 28 y -= 1	while y > 28: y -= 1	Colon missing after while.	Python
class Item {{ int z; }} obj.z=5;	class Item {{ public int z; }} obj.z=5;	Make field public.	Java
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
x = 5; if x > 3, disp('large'), end	x = 5; if x > 3, disp('large'), end	Correct.	MATLAB
'value' + 38	'value' + str(38)	Can't add int to string.	Python
def compute(): print('output')	def compute(): print('output')	Indent function body.	Python
name: data age: 33	name: data age: 33	Correct.	YAML
if (val = 1) {{}}	if (val == 1) {{}}	Use ==.	Java
int* p = nullptr; *p=5;	int* p = new int; *p=5;	Allocate memory.	C++
let mut x=14; let r1=&mut x; let ref2=&mut x;	let mut x=14; {{ let r1=&mut x; }} let ref2=&mut x;	Only one mutable borrow.	Rust
public static void main(String[] args) {{}}	public static void main(String[] args) {{}}	Correct.	Java
WHERE id = '20'	WHERE id = 20	Don't quote integer.	SQL
function compute(num) print(num) end	function compute(num) print(num) end	Correct.	Lua
x := 28	x := 28	Correct.	Go
val item = 'result'	val item = "result"	Double quotes.	Kotlin
lambda x: x+1	lambda x: x+1	Correct lambda.	Python
if (bar = 97)	if (bar == 97)	Use ==.	Scala
'67' + 61	67 + 61	Avoid string coercion.	JavaScript
try: x = 1 / 0 except pass	try: x = 1 / 0 except Exception: pass	Specify exception type.	Python
'world' + 75	'world' + 75.to_s	Convert int.	Ruby
if (c = 28) {{}}	if (c == 28) {{}}	Use ==.	Kotlin
data[39]	if data.indices.contains(39) {{ data[39] }}	Check index.	Swift
if bar = 33 {{}}	if bar == 33 {{}}	Use ==.	Swift
$x = 5; if ($x -eq 5) { Write-Host 'yes' }	$x = 5; if ($x -eq 5) { Write-Host 'yes' }	Correct.	PowerShell
.Person {{ color: red; }}	.Person {{ color: red; }}	Correct.	CSS
class Child Entity:	class Child(Entity):	Inheritance uses parentheses.	Python
[x*x for x in values if x > 16]	[x*x for x in values if x > 16]	Correct list comprehension.	Python
$values[54] = 5;	if (isset($values[54])) $values[54] = 5;	Check existence.	PHP
function baz() {{ return {{key:'value'}} }}	function baz() {{ return {{key:'value'}}; }}	Return object on same line.	JavaScript
let z = 7; let z = 64;	let z = 7; z = 64;	Duplicate declaration.	JavaScript
if (c = 37)	if (c == 37)	Use ==.	C++
else print('result')	else: print('result')	Colon after else.	Python
fmt.Println 'result'	fmt.Println('result')	Missing parentheses.	Go
["hello", 89]	["hello", 89]	Correct.	JSON
#header {{ color: #fff; }}	#header {{ color: #fff; }}	Correct.	CSS
<person age=85>	<person age="85">	Quote attribute.	XML

echo 'data'

echo 'data';

Add semicolon.

PHP

Correct.

XML

Order.save();

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

Handle promise.

Node.js

val temp: Int = 'message'

val temp: String = 'message'

Fix type.

Kotlin

raise 'hello'

raise Exception('hello')

Raise needs an exception class.

Python

var x = 85;

Correct.

Dart

Remove trailing comma.

JSON

Double quotes.

XML

if (b = 65) {}

if (b == 65) {}

Use ==.

Dart

fn handle() -> i32 {{ 66 }}

Correct.

Rust

let z: number = 'hello';

let z: string = 'hello';

Fix type.

TypeScript

object Item {{ def main(args: Array[String]) = println("result") }}

object Item {{ def main(args: Array[String]): Unit = println("result") }}

Add return type Unit.

Scala

Close li.

HTML

<hr>

Self-closing.

HTML

Add alt text.

HTML

<br>

Self-closing.

HTML

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(42);

const express = require('express'); const app = express(); app.get('/', (req,res) => res.send('data')); app.listen(42, () => console.log('listening'));

Add callback.

Node.js

div {{ color=red; }}

div {{ color: red; }}

Use colon.

CSS

String c = 'hello';

String c = "hello";

Double quotes.

Java

void main() {{ print('info') }}

void main() {{ print('info'); }}

Add semicolon.

Dart

package main func main() {{}}

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

Import needed.

Go

local c = 70

Correct.

Lua

ArrayList list = new ArrayList();

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

Use generics.

Java

let temp = 91;

Correct.

JavaScript

type MyType = string | number; let x: MyType = true;

type MyType = string | number; let x: MyType = 'hello';

Type not in union.

TypeScript

list: - item1 - item2

Correct.

YAML

baz

baz()

Add parentheses.

Swift

let z: Int = 'data'

let z: String = 'data'

Fix type.

Swift

String name = 'info';

Correct.

Dart

SELECT COUNT(*) FROM orders

SELECT COUNT(*) FROM orders;

Missing semicolon.

SQL

var x = 5; x = "hello"

var x = "hello"

Type mismatch.

Swift

$x = 5; print $x

$x = 5; print $x;

Missing semicolon.

Perl

yield z

Correct yield.

Python

my @arr = (17,44,62);

Correct.

Perl

item == '34'

item === 34

Use strict equality.

JavaScript

assert x > 19

Correct.

Python

function foo(): void {{ return 79; }}

function foo(): number {{ return 79; }}

Return type mismatch.

TypeScript

SELECT * FROM orders WHRE email=76;

SELECT * FROM orders WHERE email=76;

Fix WHERE.

SQL

let vec=vec![15,17,78]; let first=&vec[0]; vec.push(76);

let mut vec=vec![15,17,78]; let first=vec[0]; vec.push(76);

Copy instead of reference.

Rust

const index;

const index = 94;

Initialize const.

JavaScript

// comment

/* comment */

Use /* */.

CSS

<div><p>message</div></p>

<div><p>message</p></div>

Nest properly.

HTML

if foo > 33 print('info')

if foo > 33: print('info')

Colon missing after if.

Python

match a {{ 1 => {{}} }}

match a {{ 1 => {{}} _ => {{}} }}

Match must be exhaustive.

Rust

class User {{ int item; }};

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

Make public.

C++

items[68]

if (length(items) >= 68) items[68]

Check length.

R

class Order def method end end

Correct.

Ruby

if (result = 35)

if (result == 35)

Use ==.

R

render

render()

Add parentheses.

Kotlin

num = world

num = 'world'

Quote strings.

Python

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

Correct.

Shell

if ($item = 27) {{}}

if ($item -eq 27) {{}}

Use -eq.

PowerShell

<center>hello</center>

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

Use CSS.

HTML

int main() {{ return 0; }}

Correct.

C++

cin >> temp;

int temp; cin >> temp;

Declare variable.

C++

if (temp = 34) {{}}

if (temp === 34) {{}}

Use === for equality.

JavaScript

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

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

Arrow functions are cleaner.

JavaScript

System.out.println('world')

System.out.println('world');

Add semicolon.

Java

const person:Person = {{name:'result'}};

const person:Person = {{name:'result', age:47}};

Add missing property.

TypeScript

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

Correct.

R

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

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

Declare before use.

C++

$x = 5; echo $x

$x = 5; echo $x;

Missing semicolon.

PHP

int x; System.out.println(x);

int x = 0; System.out.println(x);

Initialize variable.

Java

79item = 10

item79 = 10

Variable cannot start with digit.

Python

while y > 28 y -= 1

while y > 28: y -= 1

Colon missing after while.

Python

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

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

Make field public.

Java

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

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

Correct.

MATLAB

'value' + 38

'value' + str(38)

Can't add int to string.

Python

def compute(): print('output')

Indent function body.

Python

name: data age: 33

Correct.

YAML

if (val = 1) {{}}

if (val == 1) {{}}

Use ==.

Java

int* p = nullptr; *p=5;

int* p = new int; *p=5;

Allocate memory.

C++

let mut x=14; let r1=&mut x; let ref2=&mut x;

let mut x=14; {{ let r1=&mut x; }} let ref2=&mut x;

Only one mutable borrow.

Rust

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

Correct.

Java

WHERE id = '20'

WHERE id = 20

Don't quote integer.

SQL

function compute(num) print(num) end

Correct.

Lua

x := 28

Correct.

Go

val item = 'result'

val item = "result"

Double quotes.

Kotlin

lambda x: x+1

Correct lambda.

Python

if (bar = 97)

if (bar == 97)

Use ==.

Scala

'67' + 61

67 + 61

Avoid string coercion.

JavaScript

try: x = 1 / 0 except pass

try: x = 1 / 0 except Exception: pass

Specify exception type.

Python

'world' + 75

'world' + 75.to_s

Convert int.

Ruby

if (c = 28) {{}}

if (c == 28) {{}}

Use ==.

Kotlin

data[39]

if data.indices.contains(39) {{ data[39] }}

Check index.

Swift

if bar = 33 {{}}

if bar == 33 {{}}

Use ==.

Swift

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

Correct.

PowerShell

.Person {{ color: red; }}

Correct.

CSS

class Child Entity:

class Child(Entity):

Inheritance uses parentheses.

Python

[x*x for x in values if x > 16]

Correct list comprehension.

Python

$values[54] = 5;

if (isset($values[54])) $values[54] = 5;

Check existence.

PHP

function baz() {{ return {{key:'value'}} }}

function baz() {{ return {{key:'value'}}; }}

Return object on same line.

JavaScript

let z = 7; let z = 64;

let z = 7; z = 64;

Duplicate declaration.

JavaScript

if (c = 37)

if (c == 37)

Use ==.

C++

else print('result')

else: print('result')

Colon after else.

Python

fmt.Println 'result'

fmt.Println('result')

Missing parentheses.

Go

["hello", 89]

Correct.

JSON

#header {{ color: #fff; }}

Correct.

CSS

Quote attribute.

XML