01-JS-variables.js

/* 
    =====================
    JavaScript Variables 
    =====================
*/

// Declaring (Creating) JavaScript Variables
// Value = undefined
var x;
console.log(x);

x = 5;
console.log("x = " + x);


// JavaScript Data Types
var pi = 3.14;
console.log("pi = " + pi + " which is " + typeof pi);

var number = 1;
console.log("number = " + number + " which is " + typeof number);

var username = "iSuperMostafa";
console.log("username = " + username + " which is " + typeof username);

// One Statement, Many Variables
var pi = 3.14, number = 1, username = "iSuperMostafa";

// Re-Declaring JavaScript Variables
var carName = "Volvo";
console.log("carName = " + carName);

var carName;
console.log("carName = " + carName);

// JavaScript Arithmetic
var x = 5 + 2 + 3;
console.log("x = " + x);

var x = "Mostafa" + " " + "El-Marzouki";
console.log("x = " + x);

var x = "5" + 2 + 3;
console.log("x = " + x);

var x = 2 + 3 + "5";
console.log("x = " + x);

// Much Like Algebra
var itemPrice1 = 5;
console.log("itemPrice1 = " + itemPrice1);

var itemPrice2 = 6;
console.log("itemPrice2 = " + itemPrice2);

var total = itemPrice1 + itemPrice2;
console.log(itemPrice1 + ' + ' + itemPrice2 + ' = ' + total);