Which is the correct way to write a comment in JavaScript? code example

Example 1: how to write notes in js

//this is a comment of one sentence. you dont have to close it

window.alert("hello");

/*this is a comment that lasts until it closes

you can try it!!*/

window.alert("Hi");

Example 2: comment in JavaScript

// This is how you comment a single line in JavaScript

/*
This is how you comment
multiple lines in 
JavaScript
*/