freeCodeCamp/guide/english/php/array/index.md

title
array

Introduction to PHP Array

An array can be thought of as a collection of items.

Syntax

An array is defined by array(), or [].

An example of an array in each style can be seen below:

<?php

$bikes = array('Suzuki','BMW','Yamaha');

<?php

$bikes = ['Suzuki', 'BMW', 'Yamaha'];

Key => Value

Arrays can also be defined with named keys, as shown below:

<?php

$bikes = [
    'favorite'        => 'Suzuki',
    'second favorite' => 'BMW',
    'not my favorite' => 'Yamaha'
];

Accessing Items

Items within an array can be accessed by their corresponding key, or location within the array.

For instance:

<?php

$bikes = ['Suzuki', 'BMW', 'Yamaha'];

echo 'I like '. $bikes[0];

Would produce the following output:

I like Suzuki

Another example, using named keys can be seen below:

<?php

$bikes = [
    'favorite'        => 'Suzuki',
    'second favorite' => 'BMW',
    'not my favorite' => 'Yamaha'
];

echo 'I like '. $bikes['not my favorite'];

Would produce the following output:

I like BWM

Multidimensional Array

As we mentioned earlier arrays are collection of items, often times these items may be arrays of themselves.

You will always be able to get the value for the specific key by going down the layers: $arr['layerOne']['two']

Pitfalls

When working with arrays, there are a few important things to keep in mind:

1. A comma after the last element is optional.
2. Named keys must be escaped to be accessed (i.e. $bikes[not my favorite] would not work).

For more information, please see PHP: Arrays