求任意数字累加和

/*
 * 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;
    }
}