php determines whether it is an empty array

In PHP programming, judging whether an array is empty is a very basic requirement. Here, we will introduce several methods to determine whether an array is empty.

Method 1: Use count()

In PHP, count() is a common function used to get the number of elements in an array. It is very simple to use it to determine whether an array is empty. You only need to pass the array parameter to be determined, and then determine whether the return value is 0.

The following is a sample code:

<?php
$arr = array();
if(count($arr) == 0){
    echo '数组为空';
}else{
    echo '数组不为空';
}
?>

Method 2: Use empty()

empty() is another commonly used function, used to determine whether a variable is empty. When passing an array as a parameter, a Boolean value true is returned if the array is empty, otherwise false is returned.

The following is a sample code:

<?php
$arr = array();
if(empty($arr)){
    echo '数组为空';
}else{
    echo '数组不为空';
}
?>

Method 3: Use array_diff()

This method is suitable for situations when there may be null or false values ​​in the array. Use the array_diff() function to make a difference between the array to be judged and an array containing only null and false. If the returned array is empty, it means that the array to be judged is empty.

The following is a sample code:

<?php
$arr = array();
if(array_diff($arr, array(null,false)) == array()){
    echo '数组为空';
}else{
    echo '数组不为空';
}
?>

The above are three common PHP methods for determining whether an array is empty. You can choose the appropriate method in the code according to actual needs.

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