What is an Array?
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="Volvo";
$cars2="BMW";
$cars3="Toyota";
However, what if you want to loop through the cars and find a specific one? And what if you had not 3 cars, but 300?
The solution is to create an array!
An array can hold many values under a single name, and you can access the values by referring to an index number.
Create an Array in PHP
In PHP, the array() function is used to create an array:
In PHP, there are three types of arrays:
- Indexed arrays - Arrays with numeric index
- Associative arrays - Arrays with named keys
- Multidimensional arrays - Arrays containing one or more arrays
PHP Indexed Arrays
There are two ways to create indexed arrays:
The index can be assigned automatically (index
always starts at 0):
$cars=array("Volvo","BMW","Toyota");
or the index can be assigned manually:
$cars[0]="Volvo";
$cars[1]="BMW";
$cars[2]="Toyota";
The following example creates an indexed array named $cars, assigns three
elements to it, and then prints a text containing the array values:
Example
<?php
$cars=array("Volvo","BMW","Toyota");
echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . ".";
?>
Get The Length of an Array - The count() Function
The count() function is used to return the length (the number of elements) of
an array:
Example
<?php
$cars=array("Volvo","BMW","Toyota");
echo count($cars);
?>
Loop Through an Indexed Array
To loop through and print all the values of an indexed array, you could use a for loop, like this:
Example
<?php
$cars=array("Volvo","BMW","Toyota");
$arrlength=count($cars);
for($x=0;$x<$arrlength;$x++)
{
echo $cars[$x];
echo "<br>";
}
?>
PHP Associative Arrays
Associative arrays are arrays that use named keys that you assign to them.
There are two ways to create an associative array:
$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");
or:
$age['Peter']="35";
$age['Ben']="37";
$age['Joe']="43";
The named keys can then be used in a script:
Example
<?php
$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");
echo "Peter is " . $age['Peter'] . " years old.";
?>
Loop Through an Associative Array
To loop through and print all the values of an associative array, you could use a foreach loop, like this:
Example
<?php
$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");
foreach($age as $x=>$x_value)
{
echo "Key=" . $x .
", Value=" . $x_value;
echo "<br>";
}
?>
