比较器Compare升序降序

package com.itheima.d1_set;


import sun.plugin.javascript.navig.Array;

import java.util.Arrays;
import java.util.Comparator;

public class SetDemo4 {
    public static void main(String[] args) {
        Integer array[]  ={10,3,7,2,20,24};
        Arrays.sort(array,new Comparator(){
            @Override
            public int compare(Integer t1, Integer t2) {
                return t1-t2;    //升序
            }
        });
        

        for (Integer arrays : array){
            System.out.print(arrays+" ");
        }
    }
}


结果：2 3 7 10 20 24 

package com.itheima.d1_set;


import sun.plugin.javascript.navig.Array;

import java.util.Arrays;
import java.util.Comparator;

public class SetDemo4 {
    public static void main(String[] args) {
        Integer array[]  ={10,3,7,2,20,24};

        Arrays.sort(array, new Comparator() {
            @Override
            public int compare(Integer t1, Integer t2) {
                return t2-t1;           //降序
            }
        });

        for (Integer arrays : array){
            System.out.print(arrays+" ");
        }
    }
}


结果：24 20 10 7 3 2 

发现：public int compare(Integer t1, Integer t2) {
                return t1-t2;    //升序
            }

                public int compare(Integer t1, Integer t2) {
                return t2-t1;    //降序
            }

即：当返回的参数名称与形参名顺序相同时，则为升序。反之为降序。