java作业-0511

import java.util.Random;
class zuoye 
{
    public static void main(String[] args) 
    {
        //随机点名
        /*String[] arr = {"董斌","张锐","王荣臣","韩凯","张禄","刘继勋","张维","牛攀","魏中豪"};
        for(int i = 0;i*/


        //数组的概念?有什么特点?
        //概念：一组数据的集合，数组中的每个数据被称作元素
        //特点：数组中可以存放任意类型的元素，但同一个数组里存放的元素类型必须一致

        //一维数组的定义格式?
        //数据类型[] 数组名 = new 数据类型[元素个数或数组长度];
        //类型[] 数组名 = {元素，元素，元素，……};

        //数组操作的两个小问题?
        //数组越界异常
        //空指针异常

        //数组遍历最大值
        int[][] arr1 = {{12,13},{15,16,17},{18,99,66}};
        int max = arr1[0][0];
        int min = arr1[0][0];
        /*for(int i = 0;i=max){
                 max = arr1[i][j];
              }
           }
        }
        System.out.println(max);*/


        /*for(int i = 0;i*/


        //数组逆序
        /*for(int i = arr1.length-1; i>=0; i--){
           for(int j = arr1[i].length-1; j>=0; j--){
               System.out.println(arr1[i][j]);
               
               
               }
               
               }*/
        //题目 二维遍历及求和
        int[][] arr2 = {{22,66,44},{77,33,88},{25,45,65},{11,66,99}};
        for(int i = 0;i){
           for(int j = 0;j){
              System.out.println(arr2[i][j]);
           }
        }
        System.out.println();
        int sum = 0;
        int sum1 = 0;
        for(int i = 0;i){
           for(int j = 0;j){
              sum+=arr2[i][j];
              sum1+=arr2[i][j];
           }
           System.out.println("第"+(i+1)+"季度销售额："+sum1);
           sum1 = 0;
        }
        System.out.println("总销售额为："+sum);
    }
}

 

转载于:https://www.cnblogs.com/yelena-niu/p/9035237.html