There are several ways to write php arrays

PHP arrays can be written in a variety of ways, such as indexed arrays, associative arrays, multidimensional arrays, short array syntax, and dynamically created arrays. Detailed description: 1. Index array is the most common array type, using numbers as key values ​​to access array elements; 2. Associative arrays use strings as key values ​​to access array elements, and each element has a unique key value. The corresponding value can be accessed through this key value; 3. Multi-dimensional array refers to an array containing other arrays as elements. Another array can be nested in an array to form a multi-dimensional array structure; 4. Short array syntax, etc.

The operating environment of this article: Windows 10 system, PHP8.1.3 version, Dell G3 computer.

In PHP, an array is a special data type used to store multiple values. There are many ways to write PHP arrays, including the following:

Index array:

Index array is the most common array type, which uses numbers as key values ​​to access Array elements. Array elements can be accessed through subscripts, which start counting from 0. Here is an example:

$numbers = array(1, 2, 3, 4, 5);
echo $numbers[0]; // 输出 1

Associative arrays:

Associative arrays use strings as key values ​​to access array elements. Each element has a unique key through which the corresponding value can be accessed. Here is an example:

$person = array("name" => "John", "age" => 30, "city" => "New York");
echo $person["name"]; // 输出 John

Multidimensional array:

A multidimensional array is an array that contains other arrays as elements. An array can be nested within another array to form a multidimensional array structure. Here is an example:

$students = array(
    array("name" => "John", "age" => 20),
    array("name" => "Jane", "age" => 22),
    array("name" => "David", "age" => 21)
);
echo $students[1]["name"]; // 输出 Jane

Short array syntax:

Starting with PHP version 5.4, a simplified array syntax called short array syntax was introduced. Arrays can be created more concisely using short array syntax. The following is an example:

$colors = ["red", "blue", "green"];
echo $colors[0]; // 输出 red

Dynamic creation of arrays:

In addition to using array literals to create arrays, you can also use some functions to dynamically create arrays. For example, use the range() function to generate a continuous array, and use the array_fill() function to generate an array with a specified length and default value. The following is an example:

$numbers = range(1, 5); // 创建一个包含1到5的数组
$filledArray = array_fill(0, 5, "default"); // 创建一个长度为5，值都为"default"的数组

Summary

PHP arrays can be written in a variety of ways, such as indexed arrays, associative arrays, multidimensional arrays, short array syntax, and dynamically created arrays. According to specific needs, you can choose a suitable array writing method to handle different data structures and operations.

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