57 lines
2.1 KiB
Markdown
57 lines
2.1 KiB
Markdown
---
|
|
title: Arrays
|
|
---
|
|
## Arrays
|
|
|
|
Arrays are like regular variables, but hold multiple values in an ordered list. This can be useful if you have multiple values that are all related to each other, like a list of student names or a list of capital cities.
|
|
|
|
### Types Of Arrays
|
|
In PHP, there are two types of arrays: Indexed arrays and Associative arrays. Each has their own use and we'll look at how to create these arrays.
|
|
|
|
### Indexed Array Example
|
|
An indexed array is a list of ordered values. Each of these values in the array is assigned an index number. Indexes for arrays always start at `0` for the first value and then increase by one from there.
|
|
|
|
```php
|
|
<?php
|
|
$shopping_list = array("eggs", "milk", "cheese");
|
|
```
|
|
`$shopping_list[0]` would return `"eggs"`, `$shopping_list[1]` would return `"milk"`, and `$shopping_list[2]` would return `"cheese"`.
|
|
|
|
### Associative Array Example
|
|
An associative array is a list of values that are accessed via a key instead of index numbers. The key can be any value but it must be unique to the array.
|
|
|
|
```php
|
|
<?php
|
|
$student_scores = array("Joe" => 83, "Frank" => "93", "Benji" => "90");
|
|
```
|
|
`$student_scores['Joe']` would return `83`, `$student_scores['Frank']` would return `93`, `$student_scores['Benji']` would return `90`.
|
|
|
|
### Multidimensional Array Example
|
|
A multidimensional array is an array that contains other arrays. This lets you create complex data structures that can model a very complex group of data.
|
|
```php
|
|
<?php
|
|
$students =
|
|
array(
|
|
array("first_name" => "Joe", "score" => 83, "last_name" => "Smith"),
|
|
array("first_name" => "Frank", "score" => 92, "last_name" => "Barbson"),
|
|
array("first_name" => "Benji", "score" => 90, "last_name" => "Warner")
|
|
);
|
|
```
|
|
|
|
Now you can get the first student's `first_name` with:
|
|
```PHP
|
|
$students[0]['first_name']
|
|
```
|
|
|
|
### 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:
|
|
```php
|
|
<?php
|
|
<?php
|
|
$cars = array("Volvo", "BMW", "Toyota");
|
|
echo count($cars);
|
|
?>
|
|
```
|
|
|
|
#### More Information:
|
|
* <a href="https://secure.php.net/manual/en/language.types.array.php" rel="nofollow">php.net arrays manual</a> |