How to determine if a php array is empty

In PHP, when we use arrays, sometimes we need to determine whether an array is empty. Because if we iterate over an empty array or try to use an index that is not defined in the array, an error will occur. So, how to determine whether a PHP array is empty?

1. Use the count() function to determine whether the array is empty

The count() function is a function in PHP used to check the number of array elements. When the given array is empty , the function will return 0. Therefore, we can use count() function to check if the array is empty.

The following is a sample code that uses the count() function to determine whether the array is empty:

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

The output result of the above code is: the array is empty.

2. Use the empty() function to determine whether the array is empty

The empty() function is a function in PHP used to check whether a variable is empty. This function will return TRUE when the given variable is empty. Therefore, we can use the empty() function to check if the array is empty.

The following is a sample code that uses the empty() function to determine whether the array is empty:

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

The output result of the above code is: the array is empty.

3. Use the foreach() function to determine whether an array is empty

Use the foreach() function to check whether an array is empty. When the given array is empty, the foreach() loop will not be executed, so we can use this feature to determine whether an array is empty.

The following is a sample code that uses the foreach() function to determine whether the array is empty:

<?php
    $arr = array();
    foreach($arr as $value){
        echo "数组不为空";
    }
    echo "数组为空";
?>

The output result of the above code is: the array is empty.

Summary

The above are three methods to determine whether a PHP array is empty. We can choose one of them according to actual needs to determine whether the array is empty. Before using an array, make sure it is not empty, otherwise an error may occur.

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