What is a PHP array? What are the types of PHP arrays?

What is a PHP array?

An array is a collection of data that organizes a series of data to form an operable whole.

Arrays in PHP are more complex, but more flexible than arrays in many other high-level languages. An array is an ordered set of variables, where each variable is called an element. Each element is distinguished by a special identifier, called a key (also called a subscript).

Each element in the array contains two items: key and value. The corresponding array elements can be obtained by key values, which can be numerical keys or associated keys.

If a variable is a container that stores a single value, then an array is a container that stores multiple values. The data structure is as follows:

For example, a team usually has dozens of people, but when you get to know them, you will first regard them as members of a certain team. Then use their numbers to distinguish each player. At this time, the team is an array, and the number is the subscript of the array. When you specify the player number, you can find the player!

<?php
$arr = array(0=>"tom",1=>"andy",2=>"jack");
?>

Arrays provide a quick and convenient way to manage a group of related data and are an important part of PHP programming. How to use php specifically? Please refer to the article How to declare an array in PHP: Two ways to declare an array.

What are the types of PHP arrays?

PHP arrays are divided into three categories

Numeric index array:

Indexed array Stores an organized sequence of single or multiple values, each of which can be accessed using an unsigned integer value.

Associative array:

"association Array " is an array with a special indexing method. It can be indexed not only by integers, but also by strings or other types of values ​​(except NULL).

Multi-dimensional array:

Concept in data structure, array above two-dimensional array, neither linear nor planar The array becomes multidimensional array.

We will introduce the types of PHP arrays in detail later!

【Related tutorial recommendations】

1. Relevant topic recommendations: "php array (Array) 》

2. Related video course recommendations: 《Definition and classification of php arrays: Array elements are composed of key names and values》

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