What are the two types of php arrays?

In PHP, an array is a variable that can store multiple values. They can store different types of data, including integers, floating point numbers, strings and objects. Generally, PHP arrays can be divided into two types: indexed arrays and associative arrays.

1. Index array

Index array refers to an array type that uses numerical indexes to access and store array elements. These numerical indices are called "key values", and they usually start at 0 and increase. For example, the following is an example of an integer-indexed array:

$numbers = array(1, 2, 3, 4, 5);

In the above array, the element with key 0 corresponds to value 1, the element with key 1 corresponds to value 2, and so on. The elements in an indexed array do not have to be in numerical order, nor do they have to be consecutive numeric values.

PHP provides many functions to operate and process indexed arrays, such as array_push() for adding new elements at the end of the array, count() for calculating the length of the array, and sort() for array elements. Sort etc.

2. Associative array

Associative array is an array type that uses string index to access and store array elements. These string indexes are called "keynames", and they can be any string value. For example, the following is an example of an associative array:

$interests = array('music' => 'rock', 'books' => 'mystery', 'sports' => 'football');

In the above array, the key names are 'music', 'books' and 'sports', and the corresponding values ​​are 'rock', 'mystery' and 'football'. The elements in an associative array do not have to be in any specific order.

PHP provides many functions to operate and process associative arrays. For example, array_key_exists() is used to check whether the key name exists in the array, array_values() is used to return all the values ​​​​in the array, and asort() is used to Sort by key-value pairs and so on.

Summary

There are two types of arrays in PHP: indexed arrays and associative arrays. Indexed arrays use numeric indexes to access and store array elements, while associative arrays use string indexes to access and store array elements. No matter what type of array they are, PHP provides many useful functions to operate and process them.

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