why use var in javascript code example

Example 1: js variable

var Number = 5;
var String = "Hi!";
var boolen1 = true;
var boolen2 = false;
var array = [11, "Hi!", true];
var object = {age:11, speach:"Hi!", likes_Bananas:true};

Example 2: how to define variable in javascript

var <variable-name>;

var <variable-name> = <value>;

Example 3: var javascript

var text = "";
var i;
for (i = 0; i < 5; i++) {
  text += "The number is " + i + "<br>";
}