PHP Array

In PHP, the array() function is used to create an array:

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

$cars=array("Volvo","BMW","Toyota");

or the index can be assigned manually:

$cars[0]="Volvo";
$cars[1]="BMW";
$cars[2]="Toyota";

-----------------------------------------
$cars=array("Volvo","BMW","Toyota");
echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . ".";

The output will be:
I like Volvo, BMW and Toyota.
---------------------------------------------
Loop through an indexed array

$cars=array("Volvo","BMW","Toyota");
$arrlength=count($cars);

for($x=0;$x<$arrlength;$x++) {
   echo $cars[$x];

}

The output will be:
Volvo
BMW
Toyota

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:

$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");
echo "Peter is " . $age['Peter'] . " years old.";

The output will be:
Peter is 35 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:

$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");

foreach($age as $x=>$x_value) {
  echo "Key=" . $x . ", Value=" . $x_value;
  echo "
";
}

The output will be:

Key=Peter, Value=35
Key=Ben, Value=37
Key=Joe, Value=43

A multidimensional array is an array containing one or more arrays.

PHP understands multidimensional arrays that are two, three, four, five, or more levels deep. However, arrays more than three levels deep are hard to manage for most people.

Note: The dimension of an array indicates the number of indices you need to select an element.

For a two-dimensional array you need two indices to select an element

For a three-dimensional array you need three indices to select an element

$cars = array
  (
  array("Volvo",22,18),
  array("BMW",15,13),
  array("Saab",5,2),
  array("Land Rover",17,15)
  );
  
 Now the two-dimensional $cars array contains four arrays, and it has two indices: row and column.

To get access to the elements of the $cars array we must point to the two indices (row and column):

echo $cars[0][0].": In stock: ".$cars[0][1].", sold: ".$cars[0][2];
echo $cars[1][0].": In stock: ".$cars[1][1].", sold: ".$cars[1][2];
echo $cars[2][0].": In stock: ".$cars[2][1].", sold: ".$cars[2][2];
echo $cars[3][0].": In stock: ".$cars[3][1].", sold: ".$cars[3][2];

The output will be:

Volvo: In stock: 22, sold: 18.
BMW: In stock: 15, sold: 13.
Saab: In stock: 5, sold: 2.
Land Rover: In stock: 17, sold: 15.
-----------------------------------------------

Three Dimensional Array:

ARRAY0 {
        key0.0 => "value0.0",
        key0.1 => "value0.1",
        key0.2 => ARRAY1 {
                          key1.0 => "value1.0",
                          key1.1 => ARRAY2 {
                                            key2.0 => "value2.0",
                                            key2.1 => "value2.1",
                                    },
                          key1.2 => "value1.2",
                  },
        key0.3 => "value0.3",
};