10.16

package jhe;

import java.util.*;

public class jihetext {

    public static void main(String[] args) {
        
        ArrayList<Object> al1 = new ArrayList<>();
        
        al1.add("sdad");
        
        
        List<String> al = new ArrayList<>();
        
        al.add("abc");
        
        System.out.println("集合大小"+ al.size());
        
        al.add("def");
        
        al.clear();//清除
        
        al.isEmpty();
        
        System.out.println("是不是空的 = "+ al.isEmpty());

        //System.out.println("集合大小"+ al.size());
        
        //System.out.println("集合内容"+ al.get(0));
        
        for (int i = 0;i< 10;i++)
        {
            al.add(String.format("%s", (Math.random()*1000)));
        }
        
        System.out.println();
        
        for (int a = 0;a <= 100;a++)
        {
            al.add("" + a);
        }
        
        al.remove(10);
        
        for(int b = 0; b < al.size();b++)
        {
            System.out.println("剩余集合内容"+ al.get(b));
        }
        //指定索引移除
        al.remove(0);
        
        al.set(0, "新的值");
        
        for (int i = 0; i < al.size(); i++)
        {
            System.out.println("集合内容" + al.get(i));
        }
        
        LinkedList<String> ll = new LinkedList<>();
        
        for (int i = 10;i> 0;i--)
        {
            ll.add("" + i);
            //al.add(String.format("%s", (Math.random()*1000)));
        }
        
        ll.add("10");
    
        for (int i = 0; i < ll.size(); i++)
        {
            System.out.println("集合内容" + ll.get(i));
        }
        
        HashSet<String>hs = new HashSet<>();
        
        hs.add("abc");
        
        hs.add("abc");
        
        for (int i = 10;i > 0;i--)
        {
            hs.add("" + i);
            //al.add(String.format("%s", (Math.random()*1000)));
        }
        
        //hs.add();
        //迭代器
        
        Iterator<String> ls = hs.iterator();
        
        while (ls.hasNext())
        {
            System.out.println("迭代 = " + ls.next());
        }
        
        TreeSet<String> ts = new TreeSet<>();
        
        ts.add("abc");
        
        for (int i = 20; i > 0; i--)
        {
            ts.add("" + i);
        }
        
        System.out.println("first = " + ts.first() + " last = " + ts.last());
        
        Iterator<String> is = ts.iterator();
        
        while(is.hasNext())
        {
            System.out.println("treeSet = " + is.next());
        }
        
        //
        for(String s : ts)
        {
            System.out.println("foreach = " + s);
        }
        
        
        //哈希Map
        HashMap<String, String> hm = new HashMap<>();
        
        hm.put("255000", "淄博");
        
        hm.put("234000", "东京热");
        
        hm.put("121000", "西京冷");
        
        
        
        System.out.println("25500对应得城市是"+hm.get("255000"));
        
        System.out.println("是否包含110000= " + hm.containsKey(234000));