Javascript Array

Array is a special kind of variable that can hold multiple values. If you recall the lesson on JS variables, we explained that variable is a container of a value.

Lets use analogy of a box. A simple variable is a box that holds one item like box containing a large chocolate cake. Now imagine array as a box that has many subdivisions and each compartment has a pastry of a different flavor.

    Box compartment 1 holds value = strawberry flavor
    Compartment 2 value= Vanilla and so on

Practically Array is many variables within one.
Why do we need Javascript Arrays / Advantages of using Arrays

    When we have to loop through many variables, it is much simpler to reference sub container id (usually called index) numbers instead of individual variable names. For example- looping through marks of students to check the highest score. Either write individual variable names OR array name 'student' and id 1 to 50. easier to loop through digits 1 to 50 than text names.
    All the data in the array is of same type like text, numerical etc. so it is easier to work with.

Syntax Define / Create Array- Method 1

First create an array, then assign values to its individual indexes.

var arrayname = new Array ();
arrayname[0] = "value";
arrayname[1] = "value";
arrayname[2] = "value";
arrayname[3] = "value"; And so on

Notice that the subcontainer IDs start from 0
Example

js array

Notice how we referred to the 3rd index the array using the document.write command to display it on browser screen.
Syntax Create Array- Method 2

Create an array and assign value in the same statement / command

var arrayname = new Array("value", "value", "value");
Example

javascript define array example

Both Methods are valid. Use the one you find easier and faster.