/* * 编写程序求 1+3+5+7+……+99 的和值*/public class MarkDome {    public static void main(String[] args) {        int add = sum(99);        System.out.println(add);        System.out.println(sum(10));   }    //累加方法    public static int sum(int num){        int sum =0;        for(int x=1;x<=num;x++){             sum += x;        }        return sum;    }}