const in javascript

                                    // var declares a variable, meaning its value will vary. 
// const declares a constant, meaning its value will remain 
// consistant and not change. 
// If your variable changes throughout the program or website, 
// declare it using a var statement. 
// Otherwise, if its value does not change, declare it using 
// a const statement. 

const myConst='A const does not change.';

var myVar='A var does change.';

var myVar=2;

                                    const b = 1; // this variable unique and can't change it. 

                                    const value = 10;
const constant = value;

                                    const elem = document.getElementById('elementID');

                                    /*The destructuring assignment syntax is a JavaScript expression that
makes it possible to unpack values from arrays, or properties from objects,
  into distinct variables.*/
  let array = [2,3]; 
  [a,b] = array;// unpacking array into var a and b
  console.log(a); //output 2
  console.log(b); //output 3
  let object = {name:"someone",weight:"500pounds"};
  let {name,weight} = object; // unpacking object into  var name and weight
  console.log(name);// output someone
  console.log(weight);//output 500pounds

//it i similar as doing this
/*
var a = array[0];
var b = array[1]
var name = object.name;
var weight = object.weight;

 */