How to delete array elements in php

In PHP, array is a very common data type. Elements in the array can be added, modified, and deleted at any time. This article will focus on how to delete array elements in PHP.

PHP There are two main ways to delete array elements:

1. unset() function deletes array elements

unset() function is a function of PHP Built-in function that can delete a specified variable or variable array. Using the unset() function to delete array elements is very simple. Just use the unset() function and pass in the key name of the element you want to delete.

The following is a simple example:

// 声明一个数组
$num_array = array(1, 2, 3, 4, 5);

// 使用 unset() 函数删除数组元素
unset($num_array[2]);

// 输出数组元素
print_r($num_array);

In the above code, we use the unset() function to delete element 3 in the array $num_array. The final array element output is:

Array ( [0] => 1 [1] => 2 [3] => 4 [4] => 5 )

2. array_splice() function deletes array elements

array_splice() function is also a built-in function of PHP and can be used to delete array elements. one or more elements and returns the deleted elements.

array_splice() function is used as follows:

array_splice(array, start, length, replacement)

Among them, the parameter description is as follows:

• array: required. The input array.
• start: required. The starting position of the element to be deleted.
• length: optional. The number of elements to remove.
• replacement: optional. Replaces the value of the deleted element (if any).

The following is an example of using the array_splice() function to delete array elements:

// 定义一个数组
$fruit = array('apple', 'banana', 'orange', 'pomegranate');

// 删除数组中第二个元素
array_splice($fruit, 1, 1);

// 输出数组元素
print_r($fruit);

In the above code, we use the array_splice() function to delete the second element in the array $fruit Element banana. The final output array element is:

Array ( [0] => apple [1] => orange [2] => pomegranate )

Note:

• If the length parameter is specified, the replacement parameter must be set at the same time.
• If the length parameter is not specified, all elements in the array starting from the element specified by the start parameter are deleted.
• If the replacement parameter is specified, a new array element is inserted after the starting position.
• If the replacement parameter is not specified, the returned array will be a list of deleted elements.

Summary:

This article introduces two methods to delete array elements in PHP: the unset() function and the array_splice() function. Both methods can be used to delete one or more elements from an array. In actual development, developers should choose the appropriate method to delete array elements based on the actual application scenario.

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