Array
An array stores multiple values in a single variable.
What is an Array?
You have already learnt that a variable is a storage area holding numbers and text. The problem is, a variable will hold only one value.An array is a special variable, which can hold more than one value, at a time.
If you have a list of items (a list of car names, for example), storing the cars in single variables could look like this:
$cars1="Saab"; $cars2="Volvo"; $cars3="BMW"; |
The best solution here is to use an array!
An array can hold all your variable values under a single name. And you can access the values by referring to the array name.
Each element in the array has its own index so that it can be easily accessed.
In PHP, there are three kind of arrays:
- Numeric array - An array with a numeric index
- Associative array - An array where each ID key is associated with a value
- Multidimensional array - An array containing one or more arrays
Numeric Arrays
A numeric array stores each array element with a numeric index.There are two methods to create a numeric array.
1. In the following example the index are automatically assigned (the index starts at 0):
$cars=array("Saab","Volvo","BMW","Toyota"); |
$cars[0]="Saab"; $cars[1]="Volvo"; $cars[2]="BMW"; $cars[3]="Toyota"; |
Example
In the following example you access the variable values by referring to the array name and index: <?php $cars[0]="Saab"; $cars[1]="Volvo"; $cars[2]="BMW"; $cars[3]="Toyota"; echo $cars[0] . " and " . $cars[1] . " are Swedish cars."; ?> |
Saab and Volvo are Swedish cars. |
Associative Arrays
An associative array, each ID key is associated with a value.When storing data about specific named values, a numerical array is not always the best way to do it.
With associative arrays we can use the values as keys and assign values to them.
Example 1
In this example we use an array to assign ages to the different persons: $ages = array("Peter"=>32, "Quagmire"=>30, "Joe"=>34); |
Example 2
This example is the same as example 1, but shows a different way of creating the array: $ages['Peter'] = "32"; $ages['Quagmire'] = "30"; $ages['Joe'] = "34"; |
<?php $ages['Peter'] = "32"; $ages['Quagmire'] = "30"; $ages['Joe'] = "34"; echo "Peter is " . $ages['Peter'] . " years old."; ?> |
Peter is 32 years old. |
Multidimensional Arrays
In a multidimensional array, each element in the main array can also be an array. And each element in the sub-array can be an array, and so on.Example
In this example we create a multidimensional array, with automatically assigned ID keys: $families = array ( "Griffin"=>array ( "Peter", "Lois", "Megan" ), "Quagmire"=>array ( "Glenn" ), "Brown"=>array ( "Cleveland", "Loretta", "Junior" ) ); |
Array ( [Griffin] => Array ( [0] => Peter [1] => Lois [2] => Megan ) [Quagmire] => Array ( [0] => Glenn ) [Brown] => Array ( [0] => Cleveland [1] => Loretta [2] => Junior ) ) |
Example 2
Lets try displaying a single value from the array above: echo "Is " . $families['Griffin'][2] . " a part of the Griffin family?"; |
Is Megan a part of the Griffin family? |
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