php標準函式庫spl之鍊錶，堆疊，佇列

雙向鍊錶類別：SplDoublyLinkedList

1. 增刪節點的方法

push：向鍊錶的尾部插入一個節點
pop：取得鍊錶中的尾部節點，並且從鍊錶中刪除這個節點；操作不會改變目前指標的位置
unshift：將一個節點插入鍊錶的頭部
shift：刪除一個鍊錶頭部節點

2. 指標操作方法

rewind：使鍊錶的目前指標指向鍊錶的頭部(即bottom)
current：取得鍊錶目前節點指標指向的元素，必須在呼叫之前先呼叫rewind。當指向的節點被刪除之後，會指向一個空節點
next：讓鍊錶目前的指標指向下一個節點，curent的回傳值隨之改變
bottom：取得鍊錶頭部元素，目前指針位置不變
top：取得鍊錶尾部元素，目前指標位置不變

3.其他方法（用法見堆疊類別）

valid：檢查鍊錶中是否還存在節點，循環輸出時，可以用作判斷
count：統計鍊錶中節點的個數
key：傳回目前節點的鍵值
offsetSet ：設定指定鍵的值,注意：如鍵為0，在鍊錶中0指向頭部即bottom，在堆疊中指向棧頂。
offunset：註銷指定鍵的值

<code><span><?</span>php
<span>/**
 * Created by 马廷广
 * User: 马廷广
 * Date: 2015/8/5
 * Time: 10:52
 */</span><span>$obj</span><span>=</span><span>new</span> SplDoublyLinkedList();
<span>$obj</span><span>-></span>push(<span>'b'</span>);
<span>$obj</span><span>-></span>push(<span>'c'</span>);
<span>$obj</span><span>-></span>unshift(<span>'a'</span>);
var_dump(<span>$obj</span>);
<span>/*   array(3) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
    [2]=>
    string(1) "c"
  }
)
*/</span><span>$obj</span><span>-></span>rewind();
var_dump(<span>$obj</span><span>-></span>current());<span>//string(1) "a"</span><span>$obj</span><span>-></span>next();
var_dump(<span>$obj</span><span>-></span>current());<span>//string(1) "a"</span>
var_dump(<span>$obj</span><span>-></span>bottom());<span>//string(1) "a"</span>
var_dump(<span>$obj</span><span>-></span>top());<span>//string(1) "c"</span>
var_dump(<span>$obj</span><span>-></span>pop());<span>//string(1) "c"</span>
var_dump(<span>$obj</span>);
<span>/*
*  array(2) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
  }
*/</span>
var_dump(<span>$obj</span><span>-></span>shift());<span>//string(1) "a"</span>
var_dump(<span>$obj</span>);
<span>/*
* array(1) {
    [0]=>
    string(1) "b"
  }
*/</span></code>

堆疊類別：繼承自SplDoublyLinkedList類別的SplStack類別

原理：堆疊類別的底層是由堆疊實現的，堆疊是一種先進後出的資料結構，所以SplStack類別的一些繼承自SplDoublyLinkedList類別的方法有一些理解上的不同，如rewind方法，spl使用rewind方法後指標會指向圖中的棧頂，push和pop操作的是棧頂元素，unshift和shift操作的是棧底元素

<code><span><?</span>php
<span>/**
 * Created by 马廷广
 * User: 马廷广
 * Date: 2015/8/5
 * Time: 11:47
 */</span><span>$stack</span><span>=</span><span>new</span> SplStack();
<span>$stack</span><span>-></span>push(<span>'a'</span>);
<span>$stack</span><span>-></span>push(<span>'b'</span>);
<span>$stack</span><span>-></span>push(<span>'c'</span>);
echo <span>$stack</span><span>-></span>count();<span>//3</span><span>$stack</span><span>-></span>rewind();
echo <span>$stack</span><span>-></span>current();<span>//c</span><span>$stack</span><span>-></span>offsetSet(<span>0</span>,<span>'d'</span>);<span>//offsetSet中0指向的是图中的栈顶,由栈顶向下递增1，2，3，4</span><span>while</span>(<span>$stack</span><span>-></span>valid()){
    echo <span>$stack</span><span>-></span>key()<span>.</span><span>"->"</span><span>.</span><span>$stack</span><span>-></span>current();
    <span>$stack</span><span>-></span>next();
}
<span>/*2->d
1->b
0->a
*/</span></code>

隊列類別：繼承自SplDoublyLinkedList類別的SplQueue類別

enqueue：進入佇列
dequeue：退出隊列
隊列類別的rewind，offsetSet等方法類似鍊錶

<code><?php
/**
 * Created <span>by</span> 马廷广
 * <span>User</span>: 马廷广
 * <span>Date</span>: <span>2015</span>/<span>8</span>/<span>5</span>
 * <span>Time</span>: <span>12</span>:<span>36</span>
 */

$obj = <span>new</span> SplQueue();
$obj->enqueue(<span>'a'</span>);
$obj->enqueue(<span>'b'</span>);
$obj->enqueue(<span>'c'</span>);
var_dump($obj);
/*    [<span>0</span>]<span>=></span>
    string(<span>1</span>) <span>"a"</span>
    [<span>1</span>]<span>=></span>
    string(<span>1</span>) <span>"b"</span>
    [<span>2</span>]<span>=></span>
    string(<span>1</span>) <span>"c"</span>
  }
*/
$obj->unshift(<span>"d"</span>);
$obj->push(<span>'e'</span>);
var_dump($obj);
/*
*  array(<span>5</span>) {
    [<span>0</span>]<span>=></span>
    string(<span>1</span>) <span>"d"</span>
    [<span>1</span>]<span>=></span>
    string(<span>1</span>) <span>"a"</span>
    [<span>2</span>]<span>=></span>
    string(<span>1</span>) <span>"b"</span>
    [<span>3</span>]<span>=></span>
    string(<span>1</span>) <span>"c"</span>
    [<span>4</span>]<span>=></span>
    string(<span>1</span>) <span>"e"</span>
  }
*/
$obj->rewind();
echo $obj->current();<span>//</span>d
$obj->offsetSet(<span>0</span>,<span>'h'</span>);
var_dump($obj);
/*
* array(<span>5</span>) {
    [<span>0</span>]<span>=></span>
    string(<span>1</span>) <span>"h"</span>
    [<span>1</span>]<span>=></span>
    string(<span>1</span>) <span>"a"</span>
    [<span>2</span>]<span>=></span>
    string(<span>1</span>) <span>"b"</span>
    [<span>3</span>]<span>=></span>
    string(<span>1</span>) <span>"c"</span>
    [<span>4</span>]<span>=></span>
    string(<span>1</span>) <span>"e"</span>
  }
*/</code>

版權聲明：本文為部落客原創文章，未經部落客允許不得轉載。

以上就介紹了php標準庫spl之鍊錶，堆疊，隊列，包括了方面的內容，希望對PHP教程有興趣的朋友有所幫助。