New functions supporting arrays in PHP8 make array operations more convenient

PHP is a commonly used Web programming language and has become the preferred development language for many Web applications. In PHP8, many useful functions and features have been added. One of the changes that deserves attention is the optimization of array operations.

Many new functions for arrays have been added to PHP8, making it easier for developers to write efficient code and reduce common errors in code. In this article, we will introduce some useful array functions in PHP8 and show how to use them to improve your PHP programming skills.

1. array_is_list() function
   array_is_list() function is used to check whether an array is a "list array", that is, whether the index in the array starts from 0 and continues to increase. Returns true if the array is an array of lists, false otherwise.

For example, consider the following array:

$arr = [0 => 'a', 1 => 'b', 2 => 'c'];

This array is a list array because its indexes are continuously increasing. Use the array_is_list() function to determine whether it is a list array:

if (array_is_list($arr)) {
    echo "这是一个列表数组
";
} else {
    echo "这不是一个列表数组
";
}

2. array_contains() function
   array_contains() function is used to check whether an array contains a certain value. The function returns true if the array contains at least one element equal to the specified value, otherwise it returns false.

In the following example, we use array_contains() to check whether an array contains the specified element:

$arr = [0 => 'a', 1 => 'b', 2 => 'c'];

if (array_contains($arr, 'b')) {
    echo "这个数组包含'b'
";
} else {
    echo "这个数组不包含'b'
";
}

3. array_partition() function
   array_partition() function Used to split an array into two sub-arrays based on the return value of the callback function. The callback function should return a boolean value to determine into which subarray the array element should be allocated.

The following example splits an array into an array containing even numbers and an array containing odd numbers:

$arr = [1, 2, 3, 4, 5, 6];

$func = function ($item) {
    return ($item % 2 === 0);
};

list($even, $odd) = array_partition($arr, $func);

print_r($even);
print_r($odd);

This will output the following result:

Array
(
    [1] => 2
    [3] => 4
    [5] => 6
)

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

4. array_key_first() and array_key_last() functions
   The array_key_first() function is used to return the first key (that is, the index value) of the array, while the array_key_last() function is used to return the last key of the array.

The following example shows using these two functions to get the first and last key of an array:

$arr = [0 => 'a', 1 => 'b', 2 => 'c'];

$firstKey = array_key_first($arr);
$lastKey = array_key_last($arr);

echo "第一个键是： $firstKey 
";
echo "最后一个键是： $lastKey 
";

This will output the following results:

第一个键是： 0
最后一个键是： 2

Summary
These array functions in PHP8 can help developers operate arrays more efficiently and improve programming efficiency and code quality. With the popularity and use of PHP8, these new functions are gradually being widely used in daily web development work.

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