Ds\Deque::count()函数是PHP中的内置函数, 用于获取Deque中的元素数。
语法如下：
public Ds\Deque::count( void ) : int参数：此函数不接受任何参数。
返回值：此函数返回双端队列中的元素数。
下面的程序说明了Ds\Deque::count()PHP中的功能：
程序1：
<?php
//Declare a deque
$deck = new \Ds\Deque([1, 2, 3, 4, 5, 6]);
echo ( "Elements in the Deque\n" );
//Display the Deque elements
print_r( $deck );
echo ( "\nNumber of elements in the Deque: " );
print_r( $deck -> count ());
?>输出如下：
Elements in the Deque
Ds\Deque Object
(
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[4] => 5
[5] => 6
)
Number of elements in the Deque: 6程序2：
<?php
//Declare a deque
$deck = new \Ds\Deque([ "geeks" , "for" , "geeks" ]);
echo ( "Elements in the Deque\n" );
//Display the Deque elements
print_r( $deck );
echo ( "\nNumber of elements in the Deque: " );
print_r( $deck -> count ());
?>输出如下：
Elements in the Deque
Ds\Deque Object
(
[0] => geeks
[1] => for
[2] => geeks
)
Number of elements in the Deque: 3参考： http://php.net/manual/en/ds-deque.count.php
