Answers for "const javascript"

var or 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 in javascript

// The const keyword was introduced in ES6 (2015).

// Variables defined with const cannot be Redeclared.

// Variables defined with const cannot be Reassigned.

// Variables defined with const have Block Scope.

js define constant by element id

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

const {} = object in javascript

/*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;

 */

const javascript

// `let` vs `var` vs `const` in 'javascript'

"let" allows you to declare local variable whose scope 
      is limited to the block statement.

"var" allows you to declare a variable globally or locally 
      to an entire function.

"Const" just like let, are block-scoped.
        It's value can't be reassigned and it can't be redeclared.

constants in js

static methodName() { ... }
static propertyName [= value];