Java Collection LinkedList Common instance operation, example description

I. LinkedList COMMON operations

Package list related;/** * LinkedList link list * LinkedList: The underlying data structure used by the table. Features: Fast and easy to delete, query speed slightly slower; */import Java.util.iterator;import java.util.linkedlist;class linkedlist_test {public static void Mai        N (string[] args) {LinkedList linkedlist = new LinkedList ();        LinkedList linkedlist1 = new LinkedList ();        Linkedlist1.add ("what");//Linkedlist1.add ("Zhangj");        /** */System.out.println ("------------new Operation------------");        add element Linkedlist.add at the tail ("what");        Linkedlist.add ("?");        add element Linkedlist.add (1, "Now") at the specified location;        System.out.println (LinkedList);        add Element Linkedlist.addfirst ("one") at the top of the list;        add Element Linkedlist.addlast ("last") at the end of the list;        In the specified add element linkedlist.addall (1,LINKEDLIST1);        System.out.println (LinkedList);        /** */System.out.println ("------------query Operation------------");        System.out.println ("LinkedList list is:" +linkedlist); Get first element Object obj1 = Linkedlist.getfirSt ();        Gets the element at the specified position Object obj2 = Linkedlist.get (2);        Gets the trailing element Object obj3 = Linkedlist.getlast ();        Query the length of the list of links (number of elements) int a1= linkedlist.size ();        System.out.println ("The first element is:" +obj1+ "; the third element is:" +obj2+ "; the trailing element is:" +obj3+ "; the number of internal elements is:" +A1);        /** Modify */System.out.println ("------------Modify Operation------------");        System.out.println ("The list of previously modified lists is:" +linkedlist);        Linkedlist.set (1, "what");        SYSTEM.OUT.PRINTLN ("Modified list of linked lists:" +linkedlist);            Traversal list//through while mode to traverse Iterator it1 = Linkedlist.listiterator ();//while (It1.hasnext ()) {// System.out.println ("While:" +it1.next ()),///}///For looping through for (; It1.hasnext ();) {System.        Out.println ("For:" +it1.next ()); /** Delete * When deleting with remove, the deleted object is also removed from the delete operation. * Remove (intdex int) When the delete operation occurs, the index throws an exception if it exceeds the corner label boundary Inde        Xoutofboundsexception * However, when the poll type is used, the index will return NULL if it exceeds the corner label boundary * */System.out.println ("------------delete operation------------");        System.out.println ("Delete start list of linked lists:" +linkedlist);        Removefirstoccurrence, the first occurrence of the specified element in LinkedList linkedlist.add (1, "Now"); SYSTEM.OUT.PRINTLN ("-----begin-------------" + "linkedlist=" +linkedlist);//Linkedlist.removefirstoccurrence ("Now        ");        Removelastoccurrence, the first occurrence linkedlist.removelastoccurrence ("Now") of the specified element in LinkedList;        SYSTEM.OUT.PRINTLN ("-----End---------------" + "linkedlist=" +linkedlist);        Deletes the specified element object, the specified element is deleted, no specified element is not manipulated, and the return value is a Boolean type Object obj5 = Linkedlist.remove ("?");        SYSTEM.OUT.PRINTLN ("The element for deleting list of linked lists is:" +obj5);        Deletes an object at the specified index location linkedlist.remove (0);        The first element is deleted by index, which is equivalent to Linkedlist.remove (0);        Linkedlist.removefirst ();        Delete trailing element by index Object O = Linkedlist.removelast ();        System.out.println (O);        Delete all elements (empty list) linkedlist.clear ();        Remove and poll removal method comparison//Linkedlist.remove (9); Object Obj9=linkedlist.poll ();        System.out.println ("obj9=" +obj9); System.out.println ("End of the list of linked lists:" +linkedlist);//Other methods Introduction, not description//E-PEEK ()//Retrieve but do not delete the header of this list (the first element). E Peekfirst ()//retrieves the first element of this list without deleting it, and returns null if the list is empty. E peeklast ()//retrieves the last element of this list without deleting it, and returns null if the list is empty. E poll ()//retrieves and deletes the header of this list (the first element). E Pollfirst ()//retrieves and deletes the first element of this list, and returns null if this list is empty. E polllast ()//retrieves and deletes the last element of this list, and returns null if this list is empty.    E pop ()//The stack represented by this list pops an element. }}

Two. An in-practice operation
Concept Simple Description:
Stack: The element is advanced, similar to the Water cup filled with water;
Queue: Elemental first out, similar to water pipes;
Requirement: A functional container that implements a type stack heap or queue
1. Encapsulating a function container of a similar type stack or queue

import java.util.LinkedList;public class linkedlist_test1 {    /*实现类似栈堆或队列功能的容器*/    private LinkedList linkedlist;    //构造函数，一开始就生成一个链表队列linkedlist    linkedlist_test1(){        linkedlist = new LinkedList();    }    //定义向链表队列添加元素的功能    public void addElement(Object obj){        linkedlist.add(obj);    }    //定义一个类似栈堆功能(先进后出)    public Object ZhanDui(){        return linkedlist.removeFirst();    }    //定义一个类似队列功能(先进先出)    public Object DuiLie(){        return linkedlist.removeLast();    }    //定义一个判断linkedlsit是否为空的功能    public boolean isNull(){        return  linkedlist.isEmpty();    }

2. Call the Encapsulated class

public class Tset{public static void main(String[] args){        linkedlist_test1 test = new linkedlist_test1();        String array[] = {"what","you","want"};        test.addElement(1);        test.addElement("you");        test.addElement("and");        test.addElement(array);        //栈堆功能//        while (!test.isNull()){//            System.out.println(test.DuiLie());//        }        //队列功能        for(;!test.isNull();){            System.out.println(test.ZhanDui());        }    }}

Java Collection LinkedList Common instance operation, example description