利用linkedlist设计一个队列类

 1 //利用linkedlist设计一个队列类
 2 package classwork9;
 3 
 4 import java.util.LinkedList;
 5 import java.util.Scanner;
 6 
 7 public class Duilie {
 8     private double x;
 9     LinkedList<Double> a = new LinkedList<Double>();
10     Scanner in=new Scanner(System.in);
11     public Duilie() {
12 
13     }
14 
15     public Duilie(double x) {
16         this.x = x;
17     }
18 
19     public void push() {//入队
20         System.out.println("请输入入队元素:");
21         double y=in.nextDouble();
22         a.addFirst(y);
23     }
24 
25     public void pop() {//出队
26         System.out.println("出队元素为:"+a.getLast());
27         a.removeLast();
28     }
29 }

 1 package classwork9;
 2 
 3 public class DuTest {
 4 
 5     public static void main(String[] args) {
 6         Duilie a=new Duilie();
 7         a.push();
 8         a.push();
 9         a.push();
10         a.push();
11         a.pop();
12         a.pop();
13     }
14 
15 }