Maison >développement back-end >tutoriel php >php标准库spl之链表,堆栈,队列
双向链表类:SplDoublyLinkedList
push:向链表的尾部插入一个节点
pop:获取链表中的尾部节点,并且从链表中删除这个节点;操作不改变当前指针的位置
unshift:向链表的头部插入一个节点
shift:删除一个链表头部节点
rewind:使链表的当前指针指向链表的头部(即bottom)
current:获得链表当前节点指针指向的元素,必须在调用之前先调用rewind。当指向的节点被删除之后,会指向一个空节点
next:让链表当前的指针指向下一个节点,curent的返回值随之改变
bottom:获得链表头部元素,当前指针位置不变
top:获得链表尾部元素,当前指针位置不变
valid:检查链表中是否还存在节点,循环输出时,可以用作判断
count:统计链表中节点的个数
key:返回当前节点的键值
offsetSet :设置指定键的值,注意:如键为0,在链表中0指向头部即bottom,在堆栈中指向栈顶。
offunset:注销指定键的值
<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>$obj</span>); <span>/* * array(1) { [0]=> string(1) "b" } */</span></code>
堆栈类:继承自SplDoublyLinkedList类的SplStack类
原理:堆栈类的底层是由栈实现的,栈是一种先进后出的数据结构,所以SplStack类的一些继承自SplDoublyLinkedList类的方法有一些理解上的不同,如rewind方法,spl使用rewind方法后指针将指向图中的栈顶,push和pop操作的是栈顶元素,unshift和shift操作的是栈底元素
<code><span></span>php <span>/** * Created by 马廷广 * User: 马廷广 * Date: 2015/8/5 * Time: 11:47 */</span><span>$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>
队列类:继承自SplDoublyLinkedList类的SplQueue类
enqueue:进入队列
dequeue:退出队列
队列类的rewind,offsetSet等方法类似于链表
<code><?php /** * Created <span>by 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>
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以上就介绍了php标准库spl之链表,堆栈,队列,包括了方面的内容,希望对PHP教程有兴趣的朋友有所帮助。