Summary of commonly used functions in PHP: array_shift()

Summary of commonly used functions in PHP: array_shift()

As a popular programming language, PHP provides a rich function library, making it easier for developers to write efficient programs. Here, I would like to share with you a commonly used PHP function-array_shift().

Introduction

The array_shift() function is a function in PHP used to delete the first element in an array and return that element. It will rearrange the indexes of the array so that the new starting index in the array is 0 and increase one by one, while deleting the original first element. This method can also be used to remove a value from an array (i.e. remove the first matching value).

Syntax

array_shift(array $array): mixed

Parameter description: $array, the array to be operated on. If the argument is not an array, the function returns NULL.

Return value: This function returns the value of the deleted element. If the array is empty, NULL is returned.

Example

Let us see a simple example to understand how to use the array_shift() function:

$myArray = array('apple', 'orange', 'banana', 'grape');
$firstItem = array_shift($myArray);
print_r($myArray);
echo $firstItem;

The above code will output:

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

In this In the example, we create an array of 4 elements and use the array_shift() function to delete the first element (i.e. "apple"). The function will then return the value of the removed element, which is "apple". Finally, we print out the modified array and deleted element values.

Note:

1. If you try to call this function on something other than an array, it will return NULL.
2. If you try to delete the first element of an empty array, this function will return NULL.
3. After calling this function, the starting index of the array will become 0, and the indexes of the remaining elements will be incremented by 1.

Summary

array_shift() is a frequently used PHP function. Use it to conveniently delete the first element in an array and return that element. If you need to remove other elements from the array, you can use the array_splice() function or the unset() function. If you often use PHP to operate arrays, array_shift() will definitely become your right-hand assistant.

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