In this tutorial, we will begin learning about arrays.
What Are Arrays?
An array is a special variable that can store multiple related values; this is in contrast to regular variables that can store only one value at a time.
Why Use Arrays?
If you have a number of fruits, you can store them separate like this
<?php
$fruit1 = "orange";
$fruit2 = "apple";
$fruit3 = "mango";
?>However, one problem with using separate variables is that you lack a convenient way to loop through them.
And this is where an array is useful: it allows you to easily loop through a number of related variables using a foreach loop.
An array can hold many related values in the same variable and access each value using an index(also known as a key).
Creating an Array
To create arrays in PHP, you use the following syntax:
$arr = [];
Alternatively, you can also write:
$any = array();
The above codes do the same thing; they create an empty array.
Arrays all have some things called keys and values.
The key is which unit we are interested in; different values are stored with different keys.
Values are what each item of the array equals.
Setting specific key values is optional: by default, the keys for an array are 0,1,2,3,4,5,6 in ascending order.
Hence, the key for the first item in the array is 0 and the second item’s key is 1.
And this what you would get for this array below.
<?php
$arr =["a", "b", "c", "d"];echo $arr[0]; //$arr[0] equals a echo $arr[1]; //$arr[1] equals becho $arr[2]; //$arr[2] equals c
echo $arr[3]; //$arr[3] equals d
?>
Result
However, you are free to assign whatever key values you wish in your array.
Types Of Arrays
In PHP, there are three different types of arrays:
Indexed arrays: these are arrays with numbers as keys.
Associative array: this is a fancy way of saying “arrays where the keys are not numbers”.
Multidimensional array: these are “arrays of arrays”: the value of the keys are themselves arrays.
