集合-HashMap

1)
Map list = new HashMap();
        list.put("Isaac", "王远航");
        list.put("Jay", "周杰伦");
        list.put("Akon", "阿肯");
        //Object obj=list.values();
        System.out.println("输入你要找的姓名");
        String name = input.next();
        //Object obj=null;
        boolean flag=false;
        String name1=null;
        for(Object obj:list.values()) {
            if(obj.equals(name)) {
                flag=true;
                name1=(String)obj;
                break;
            }
        }
        if(flag==true) {
            System.out.println(name1);
        }else {
            System.out.println("没找到");
        }

3）
public class Iterator {
    public static void main(String[] args) {
        
        Map list = new HashMap();
        list.put("Isaac", "王远航");
        list.put("Jay", "周杰伦");
        list.put("Akon", "阿肯");
        
        //方法1：依次取出键值对
        //Set name2 = list.keySet();可以先拿到key的集合 然后用name2去依次赋值遍历 
        for(Object obj:list.keySet()) {
            String name1=(String)obj;
            System.out.println(name1+" "+list.get(name1));
            //因为list.get(name1)的返回值类型为collect类型所以可以强成String类型
        }
        //方法2使用Iterator迭代器
        Iterator itt = list.iterator();
        while(itt.hasNext()) {
            String names = (String)itt.next();
            String value = (String)list.get(names);
            System.out.println(names+" "+value);
            }
        //方法3先拿到Map中的键值对，然后在每对键值对中分别取出键和值
        Set ms = list.entrySet();
        for(Object obj : ms) {
            Map.Entry me =(Map.Entry)obj;
            Object key = me.getKey();
            Object value = me.getValue();
            System.out.println((String)key+(String)value);
        }
    }
    }

4）
public static void main(String[] args) {
        Ldemo2 title1 = new Ldemo2("张三",‘男‘);
        Ldemo2 title2 = new Ldemo2("李四",‘男‘);
        Ldemo2 title3 = new Ldemo2("王五",‘女‘);
        //Ldemo2 title = new Ldemo2("","");
        Map<String, Ldemo2> list = new HashMap<String, Ldemo2>();
        list.put("Isaac",title1);
        list.put("Jay",title2);
        list.put("Akon",title3);
        
        
        
        for(String obj:list.keySet()) {
            //String name1=(String)obj;
            System.out.println(obj+" "+list.get(obj).getNames());
            
        }

5)
Set<Map.Entry<String, String>> ms=list.entrySet();
        for(Map.Entry<String, String> obk:ms) {
            System.out.print(obk.getKey()+""+obk.getValue());
        }