Arrays in Javascript – The Basics

What are Arrays ?

Arrays can be used to store a list of data items. Like a list of numbers or objects.

let ageList = [15, 17, 25, 16, 14]

So if we do not use arrays then we need to declare separate variables for all the ages. Imagine if we had 100 people. Declaring 100 variables will be very inefficient.

Each element in an array is stored at an index. Indexes start from 0.

Index : 0 1 2 3 4
Value : 15 17 25 16 14

How to access elements in an array ?

It is easy to access the elements stored in the array using index.

Like if we want to get element stored at the 3rd location we can use

ageList[3]

Similarly we can assign new value to an index

ageList[3] = 32

How to find number of items in the array ?

To find the length of array or number of items in the array we can use the length property.

ageList.length

Author: codesmartly

I am Enthusiastic about Learning new things and sharing my Knowledge. I like programming and have a pretty good background in Computer Science.

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