1 public class Text1{ 2     public static void main(String args[]){ 3         System.out.println("和等于："+add(2,5)); 4         System.out.println("和等于："+add(2,5,100,25,23)); 5         System.out.println("和等于："+add()); 6         System.out.println("乘等于："+cheng(2,4)); 7         System.out.println("乘等于："+cheng(2,4,6)); 8         System.out.println("乘等于："+cheng()); 9     }10     public static int add(int ... arr){11         int num=0;12         assert arr.length==0;13         for(int lemp:arr){14             num+=lemp;15         }16         return num;17     }18     public static double cheng(double ... arr){19         if(arr.length==0)20         return 0.0;21         double num=1;22         for(double lemp:arr){23             num*=lemp;24         }25         return num;26     }27 }