package dplearn;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;



public class Learn {
	public static void main(String[] args){
		Basicinfo[] myBs=new Basicinfo[3];
		myBs[0]=new Basicinfo("虎头牌笔记本",8.5f,"red");
		myBs[1]=new Basicinfo("A4纸",25.8f,"white");
	    myBs[2]=new Basicinfo("B2铅笔",1.2f,"black");
	    Arrays.sort(myBs);
        for (Basicinfo bsinfo:myBs){
        	System.out.println(bsinfo.info());
        }
        System.out.println("------");
	    Arrays.sort(myBs,Collections.reverseOrder());
        for (Basicinfo bsinfo:myBs){
        	System.out.println(bsinfo.info());
        }
        Map<Integer, String> mymap=new HashMap<Integer, String>();
        mymap.put(1, "abc");
        mymap.put(2, "123");        
        mymap.put(3, "823");
        mymap.put(2, "qqq");//修改键值
        System.out.println("------");
        Set keys = mymap.keySet();
        for (Object key:keys){
        	System.out.println(keys+"=>"+mymap.get(key));
        }
	}
}

package dplearn;



public class Basicinfo implements Comparable{
	String name;
	float price;
	String color;
	public Basicinfo(){
		name="";
	    price=0;
	    color="";
	}
	public Basicinfo(String name,float price,String color){
		this.name=name;
		this.price=price;
		this.color=color;
	}
	public String info(){
		return "name:"+this.name+"=>price:"+this.price+"=>color:"+this.color;
	}
	@Override
	public int compareTo(Object obj) {
		// TODO Auto-generated method stub
		Basicinfo anotherBsinfo=(Basicinfo)obj;
		if (anotherBsinfo.price > this.price) {
			return 1;
		}
		else if (anotherBsinfo.price < this.price) {
			return -1;
		}	
		else{
			return 0;			
		}
	}
}

本博客所有内容是原创，如果转载请注明来源

http://blog.csdn.net/myhaspl/

name:A4纸=>price:25.8=>color:white

name:虎头牌笔记本=>price:8.5=>color:red

name:B2铅笔=>price:1.2=>color:black

------

name:B2铅笔=>price:1.2=>color:black

name:虎头牌笔记本=>price:8.5=>color:red

name:A4纸=>price:25.8=>color:white

------

[1, 2,3]=>abc

[1, 2,3]=>qqq

[1, 2,3]=>823