Java逆轉程式3.java

/*
Java逆轉程式3.java
ArraySort
使用Java官方內建的 Collections家族 來實作陣列逆轉
*/
package com.sample;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;

public class Project28 {

    public static void main(String[] args) {
        int i = 0;
        int[] i1 = { 2, 3, 1 };
        System.out.println("1. i1 = " + Arrays.toString(i1));
        Arrays.sort(i1);// 由小到大排序
        System.out.println("2. i1 = " + Arrays.toString(i1));
        Integer[] i2 = new Integer[i1.length];
        for (i = 0; i < i1.length; i++) {
            i2[i] = i1[i];
        }
        System.out.println("3. i2 = " + Arrays.toString(i2));
        Arrays.sort(i2, Collections.reverseOrder());
        System.out.println("4. i2 = " + Arrays.toString(i2));
        int[] i3 = { 6, 1, 4, 3, 5, 1 };
        ArrayList<Integer> arrayList = new ArrayList<Integer>();
        for (i = 0; i < i3.length; i++) {
            arrayList.add(i3[i]);
        }
        System.out.println("5. arrayList = " + arrayList);
        Collections.reverse(arrayList);
        System.out.println("6. arrayList = " + arrayList);
    }
}