SplDoublyLinkedList::isEmpty()

(PHP 5 >= 5.3.0, PHP 7)

Checks whether the doubly linked list is empty

说明

publicSplDoublyLinkedList::isEmpty(void) : bool

参数

此函数没有参数。

返回值

Returns whether the doubly linked list is empty.

//isEmpty is a method of SplDoublyLinkedList 
$obj = new SplDoublyLinkedList();
// Check wither linked list is empty
if ($obj->isEmpty())
{
  $obj->push(2);
  $obj->unshift(10);
}
print_r($obj);
//Output like this
SplDoublyLinkedList Object
(
  [flags:SplDoublyLinkedList:private] => 0
  [dllist:SplDoublyLinkedList:private] => Array
    (
      [0] => 10
      [1] => 2
    )
)