There are three types of php arrays:
- Indexed.
- Associative.
- Multi-Dimensional.
Indexed Arrays
- This is an array that has a numeric key. Like in JavaScript, the arrays are zero-based indexing, that is, they start counting from zero.
<?php
$cities = array('Nairobi','Mombasa','Kisumu');
?>
echo $cities[2];
The output of the above array is Kisumu.
Here is a break-down of zero-based indexing:
<?php
$cities[0] = "Nairobi";
$cities[1] = "Mombasa";
$cities[2] = "Kisumu";
?>
Associative Arrays
- This is an array where each key has its own specific value.
Example:
<?php
$cities = array('Nairobi' => 40,'Mombasa' => 60,'Kisumu'=>10);
?>
echo $cities['Nairobi'];
The above will give an output of 40 as the key 'Nairobi' is associated with that value. A break-down of the above will be as follows:
<?php
$cities['Nairobi'] = 40;
$cities['Mombasa'] = 60;
$cities['Kisumu'] = 10;
?>
Multi-dimensional Arrays
- This is an array in which each element can also be an array and each element in the sub-array can be an array or further contain an array within itself. Example:
<?php
$cars = array(
array('Honda','Toyota','Mazda'),
array('BMW','Volkswagen','Mercedes),
array('Probox','Vitz')
);
?>
echo $cars[1][2];
The output of the above example will be Mercedes. Explanation
echo $cars[1] //this will first index the multiple arrays thus array('BMW','Volkswagen','Mercedes) falls in that category
The second bit is as follows
echo $cars[2] //picks the third variable from the array picked above
Another example of a multi-dimensional:
<?php
// Define a multidimensional array
$superHeroes = array(
array(
"name" => "Bruce Wayne",
"city" => "Gotham",
),
array(
"name" => "Arthur Curry",
"city" => "Asgard",
),
array(
"name" => "Barry Allen",
"city" => "Central City",
)
);
// Access nested value
echo "The Flash's hometown is : " . $superHeroes[2]["city"];
?>
On the above example - we have combined both the Indexed and associative array, thus the output will be: The Flash's hometown is: Central City. Explanation:
echo $superHeroes[2] //picks the array to get our values from.
echo $superHeroes["city"] //gives the value of the key associated with city in the array.
This is my very first article and I hope it has helped you in understanding arrays in php. Thank you very much for reading it.