How to make a numerically indexed array in Php ?

If this is your first time seeing an array, then you may not quite understand the concept of an array. Imagine that you
own a business and you want to store the names of all your employees in a PHP variable. How would you go about this?
It wouldn't make much sense to have to store each name in its own variable. Instead, it would be nice to store all the
employee names inside of a single variable. This can be done, and we show you how below.
PHP Code:
$employee_array[0] = "Bob";
$employee_array[1] = "Sally";
$employee_array[2] = "Charlie";
$employee_array[3] = "Clare";