How to initialize array as empty in php

In PHP, array is a very common data type. Arrays can be used to store a set of related data and can be easily manipulated and processed. What if we want to create an empty array, that is, an array without any values?

There are many ways to initialize an empty array in PHP. Below we will introduce some of the commonly used methods.

Method 1: Directly assign an empty array

In PHP, you can create an empty array directly by assigning an empty array to a variable, for example:

$empty_array = array();

Or

$empty_array = [];

Both methods can create an empty array without any elements. It should be noted that in versions prior to PHP 5.4, only the array() method can be used to create an empty array, while the [] method only supports PHP 5.4 and above.

Method 2: Use array() function

In addition to directly assigning an empty array, we can also use PHP’s built-in array() function to create an empty array. For example:

$empty_array = array();

This method is essentially the same as the first method, except that it uses PHP built-in functions to create an empty array.

Method 3: Use the array_fill() function

array_fill() The function can create an array of a specified size and filled with the same values. If we set the padding value to an empty string or NULL, we can get an empty array. For example:

$empty_array = array_fill(0, 0, '');

This method will return an empty array with a length of 0. It should be noted that the first parameter represents the starting index of the array, the second parameter represents the length of the array, and the third parameter represents the value to be filled.

Method 4: Use the range() function

range() The function can quickly create an integer array within a specified range. If we set the range from 0 to -1, we can create an empty array. For example:

$empty_array = range(0, -1);

This method will return an empty array with a length of 0. It should be noted that the first parameter of the range() function is the starting value of the range, and the second parameter is the ending value of the range, which can be set to a negative number.

Summary

No matter which method is used, PHP can easily create an empty array. It should be noted that there is no fixed way to create an empty array, and different ways can achieve the same effect. Just choose the most suitable method according to actual needs.

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