在PHP中，is_array()函数用于检查给定的值是否是一个数组
示例1：检查字符串是否为数组
$str = "Hello, World!";if (is_array($str)) { echo "The given value is an array.";} else { echo "The given value is not an array.";}// 输出：The given value is not an array.示例2：检查整数是否为数组
$num = 42;if (is_array($num)) { echo "The given value is an array.";} else { echo "The given value is not an array.";}// 输出：The given value is not an array.示例3：检查多维数组是否为数组
$multi_dim_array = array( "name" => "John", "age" => 30, "city" => "New York");if (is_array($multi_dim_array)) { echo "The given value is an array.";} else { echo "The given value is not an array.";}// 输出：The given value is an array.示例4：检查对象是否为数组
class Person { public $name; public $age;}$person = new Person();$person->name = "John";$person->age = 30;if (is_array($person)) { echo "The given value is an array.";} else { echo "The given value is not an array.";}// 输出：The given value is not an array.
