How to define arrays in php

There are four ways to define arrays in PHP: square brackets define numeric or string arrays. The array keyword defines an associative array. Short array syntax (PHP 5.4) defines simple arrays of numbers or strings. The array() function defines an empty array or an initial array.

Methods of defining arrays in PHP

In PHP, there are several ways to define arrays:

1. Use square brackets ([])

The most common method is to use square brackets:

$array = array(1, 2, 3); // 定义一个由数字组成的数组

2. Use the keyword array

You can also use the array keyword to define an array:

$array = array( 'a' => 1, 'b' => 2, 'c' => 3 ); // 定义一个由键值对组成的关联数组

3. Use short array syntax (PHP 5.4)

For simplicity For a one-dimensional array, you can use short array syntax:

$array = [1, 2, 3];

4. Use the built-in function array()

You can also use the array() function to define an array:

$array = array(); // 定义一个空数组 $array = array(1, 2, 3); // 定义一个由数字组成的数组

Which method to choose

Which method to choose depends on the type and complexity of the array:

• If you want to define a simple For numeric or string arrays, it is most convenient to use square brackets or short array syntax.
• If you want to define an associative array, you can use the array keyword or short array syntax (using the => operator).
• If you want to create an empty array, you can use the array() function or empty square brackets.

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