java数组算法运用-CSDN博客

package com.itheima;

public class arraytrain {
    public static void main(String[] args) {
        //定义一个数组里面存1,2,3,4,5  求和
        int[] num = new int[]{1,2,3,4,5};
        int sum = 0;
        for (int i = 0; i < num.length; i++) {
            System.out.println(num[i]);
            sum = sum + num[i];
        }
        System.out.println(sum);


        System.out.println("-----------------------------------------");

        //定义一个数组存1,2,3,4,5,6,7,8,9,10 求有多少个能被3整除
        int count = 0;
        int[] arr1 = new int[10];

        for (int t = 1; t <= 10; t++) {
            arr1[t-1] = t;
            if(t % 3 == 0)
                count++;
        }
        System.out.println(count);



        System.out.println("-----------------------------------------");


        //定义一 个数组 存1,2,3,4,5,6,7,8,9,10
        //要求:1.奇数就扩大两倍 2.偶数就缩小两倍
        int[] arr2 = new int[10];
        for (int k = 1; k <= 10; k++) {
            arr2[k-1] = k;
            System.out.println(arr2[k-1]);

            if(arr2[k-1] % 2 == 0){
                arr2[k-1] /= 2;
            }
            else{
                arr2[k-1] *=2;
            }
            System.out.println(arr2[k-1]);
        }
    }
}