Array

A shell variable is capable enough to hold a single value. This type of variables are called scalar variables.

Shell supports a different type of variable called an array variable that can hold multiple values at the same time. Arrays provide a method of grouping a set of variables. Instead of creating a new name for each variable that is required, you can use a single array variable that stores all the other variables.

All the naming rules discussed for Shell Variables would be applicable while naming arrays.
Defining Array Values:

The difference between an array variable and a scalar variable can be explained as follows.

Say that you are trying to represent the names of various students as a set of variables. Each of the individual variables is a scalar variable as follows:

NAME01="Zara"
NAME02="Qadir"
NAME03="Mahnaz"
NAME04="Ayan"
NAME05="Daisy"

We can use a single array to store all the above mentioned names. Following is the simplest method of creating an array variable is to assign a value to one of its indices. This is expressed as follows:

array_name[index]=value

Here array_name is the name of the array, index is the index of the item in the array that you want to set, and value is the value you want to set for that item.