var variable = 10;
function start() {
variable = 20;
}
console.log(variable + 20);
// Answer will be 40 since the variable was changed in the functionvar x = 0;
function f() {
var x = y = 1; // x è dichiarata localmente. y invece no!
}
f();
console.log(x, y); // Genera un ReferenceError in strict mode (y non è definita). 0, 1 altrimenti.
// In modalità non-strict mode:
// x è la globale come si ci aspettava
// però, y è uscita fuori dalla funzione!// here are the ways to define variables
var x = "hi"; // for global variables
let x = "hi"; // for block-scoped variables
const x = "hi"; // for block-scoped variables which can not be reassignedvar is a keyword to define the varible in js but as of es-6 we, use let and const keywords for the same// This is best way to make a variable
// Varibales Store Data
var variable1 = 56;
//OR
var variable2 = true;
var variable3 = "Hello World";var a; // variable
var b = "init"; // string
var c = "Hi" + " " + "Joe"; // = "Hi Joe"
var d = 1 + 2 + "3"; // = "33"
var e = [2,3,5,8]; // array
var f = false; // boolean
var g = /()/; // RegEx
var h = function(){}; // function object
const PI = 3.14; // constant
var a = 1, b = 2, c = a + b; // one line
let z = 'zzz'; // block scope local variable