ARRAY

How to create array and add element

We can create arrays in JavaScript in different ways. Handling of arrays using JavaScript is required in many applications. If we are processing a form then elements of the form can be managed as part of an array. We will learn some different points on use of arrays and before that we will learn some basics of JavaScript array.

How to create arrays in JavaScript?

We can declare an array like this

We can add elements to this array

Now our array scrips has 4 elements inside it and we can print or access them by using their index number. Note that index number starts from 0. To get the third element of the array we have to use the index number 2 . Here is the way to get the third element of an array.

document.write(scripts[2]);

We also can create an array like this

var no_array = new Array(21, 22, 23, 24, 25);

Displaying all elements of an array

We can display all elements of an array by looping through each element of the array. Here we will increment the index of the array by one in each loop and display elements of the array one by one. To identify how many loops we have to make we must know the total number of elements present inside the array. That we can find out like this

array_name.length

So this number we will set as upper limit of our number of rotation or looping. You can check our tutorial on creating array to create an array and now we will try to display each element of the array. Here is the code.

var scripts = new Array();
scripts[0] = “PHP”;
scripts[1] = “ASP”;
scripts[2] = “JavaScript”;
scripts[3] = “HTML”;

for (i=0;i<scripts.length;i++)
{
document.write(scripts[i] + “<br >”);
}

The for loop in the above code loops through the elements of the array and display one by one vertically by adding one line break at the end of each element. The upper limit of the for loop is set to script.length value which is in this case equal to 4