What is the function in PHP to determine if an array is empty?

php's functions for determining whether an array is empty are the "empty()" function and the "count()" function. 1. The "empty()" function is used to determine whether a variable is empty, including determining whether an array is empty. Its syntax is "empty($variable)"; 2. The "count()" function is used to count arrays. The number of elements, the syntax is "count($array)".

The operating system of this tutorial: Windows10 system, PHP version 8.1.3, DELL G3 computer.

The functions used in PHP to determine whether an array is empty are empty() and count(). Below I will introduce the usage and differences of these two functions in detail.

1. Empty() function:

The empty() function is used to determine whether a variable is empty, including determining whether an array is empty. Its syntax is as follows:

empty($variable)

Among them, $variable is the variable to be judged, which can be any type of variable, including arrays. The return value of the empty() function is a Boolean value. If the variable is empty, it returns true; if the variable is not empty, it returns false.

For arrays, the empty() function determines whether the array is empty, that is, whether there are no elements in the array. Returns true if the array is empty; returns false if the array is not empty. The following is some sample code that uses the empty() function to determine whether the array is empty:

$array1 = array(); // 空数组
$array2 = array(1, 2, 3); // 非空数组
if (empty($array1)) {
    echo "数组1为空";
} else {
    echo "数组1不为空";
}
if (empty($array2)) {
    echo "数组2为空";
} else {
    echo "数组2不为空";
}

The output result is:

数组1为空
数组2不为空

As you can see, the empty() function can simply determine whether the array is empty. null.

2. count() function:

The count() function is used to count the number of elements in the array. Its syntax is as follows:

count($array)

Among them, $array is the array whose number of elements is to be counted. The return value of the count() function is an integer, indicating the number of elements in the array.

For arrays, we can use the count() function to determine whether the array is empty. If there are no elements in the array, 0 is returned; if there are elements in the array, the number of elements is returned. The following is some sample code that uses the count() function to determine whether the array is empty:

$array1 = array(); // 空数组
$array2 = array(1, 2, 3); // 非空数组
if (count($array1) == 0) {
    echo "数组1为空";
} else {
    echo "数组1不为空";
}
if (count($array2) == 0) {
    echo "数组2为空";
} else {
    echo "数组2不为空";
}

The output result is:

数组1为空
数组2不为空

As you can see, the number of elements of the array can be obtained through the count() function number, and then determine whether the array is empty.

Summary:

In PHP, you can use the empty() function and count() function to determine whether an array is empty. The empty() function directly determines whether the array is empty and returns a Boolean value; the count() function counts the number of array elements. When the number is 0, it means the array is empty. Depending on the specific situation, you can choose to use one of the functions to determine whether the array is empty.

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