java集合队列使用方法Queue

向右看齐 2022-01-31 14:13 237阅读 0赞

package com.javabase.p1;
    
    import java.util.ArrayList;
    import java.util.Collection;
    import java.util.Collections;
    import java.util.HashSet;
    import java.util.Iterator;
    import java.util.LinkedList;
    import java.util.Queue;
    import java.util.Random;
    import java.util.Set;
    
    public class DemoSet {
    	//ArrayList乱序排列
    	public static void Test_Array() {
    		ArrayList<Integer> arr = new ArrayList<>();
    		arr.add(100);
    		arr.add(101);
    		arr.add(125);
    		arr.add(185);
    		arr.add(452);
    		arr.add(789);
    		
    		
    		for (int i = 0; i < arr.size(); i++) {
    			int p = arr.get(i);
    			System.out.print(p + " ");
    		}
    		
    		System.out.println("\n");
    		
    		//乱序排列
    		Collections.shuffle(arr,new Random(521));
    		for (int i = 0; i < arr.size(); i++) {
    			int p = arr.get(i);
    			System.out.print(p + " ");
    		}
    		
    		System.out.println("\n");
    		
    		//乱序排列
    		Collections.shuffle(arr,new Random(30));
    		for (int i = 0; i < arr.size(); i++) {
    			int p = arr.get(i);
    			System.out.print(p + " ");
    		}
    		
    		
    		
    		
    		
    		
    	}
    	//HashSet集合 无序排列
    	public static void Test_set() {
    		String s = "我要去北京看故宫";
    		String s1 = "我要去深圳吃龙虾";
    		String s2 = "我要去四川吃麻辣烫";
    		String s3 = "我要去西藏吃牛肉";
    		String s4 = "我要去内蒙古骑马";
    		//Set集合 无序排列
    		Set<String> st = new HashSet();
    		st.add(s);
    		st.add(s1);
    		st.add(s2);
    		st.add(s3);
    		st.add(s4);
    		
    		
    		
    		
    		
    		st.remove(s1);
    		
    		Iterator<String> iter = st.iterator();
    		while (iter.hasNext()) {
    			String str = (String) iter.next();
    			System.out.println(str);
    			
    		}
    		
    		System.out.println();
    		
    		for (Iterator<String> itr = st.iterator();itr.hasNext();) {
    			String str = (String) itr.next();
    			System.out.println(str);
    		}
    	}
    
    	//Queue集合队列 先进先出
    	public static void Test_queue() {
    		String s = "我要去北京看故宫";
    		String s1 = "我要去深圳吃龙虾";
    		String s2 = "我要去四川吃麻辣烫";
    		String s3 = "我要去西藏吃牛肉";
    		String s4 = "我要去内蒙古骑马";
    		
    		Queue<String> qu = new LinkedList<>();
    		qu.add(s);
    		qu.add(s1);
    		qu.add(s2);
    		qu.add(s3);
    		qu.add(s4);
    		
    		
    		
    		String str2 = qu.poll(); //弹出元素
    		
    		System.out.println(str2);
    		
    		
    		System.out.println();
    		
    		qu.remove(s3);  //删除元素
    		
    		Iterator<String> it = qu.iterator();
    		while (it.hasNext()) {
    			String str = it.next();
    			System.out.println(str);
    		}
    		
    		
    	}
    	public static void main(String[] args) {
    	
    		Test_set();
    		System.out.println("==============");
    		System.out.println("\n");
    		
    		Test_queue();
    		
    		System.out.println("==============");
    		System.out.println("\n");
    		Test_Array();
    		
    		
    		
    
    	}
    
    }