输入任意个数字求和的小程序

 1 //package com;
 2 
 3 import java.util.Scanner;
 4 
 5 import javax.swing.plaf.synth.SynthSpinnerUI;
 6 
 7 public class NumPlus {
 8 
 9     public static void main(String[] args) {
10         System.out.print("How many numbers do you want to sum? ");
11         int n; //n为求和的数字的个数
12         Scanner scan = new Scanner(System.in);
13         n = scan.nextInt(); //输入n
14         double plusArray[] = new double [n];
15         //开辟内存空间，建立动态数组plusArray
16         double sum = 0; //将求和结果初始化为0
17         System.out.println("input every numbers by turn,"
18                 + "and press enter after input every number.");
19         for(int i=0;i<plusArray.length;i++) //i为计数器
20         {
21             plusArray[i] = scan.nextDouble();
22             sum = sum + plusArray[i]; //plusArray[]中的每一项叠加
23         } 
24         //此时sum的值为输入的所有数据的和
25         System.out.println("the sum of these numbers is " + sum);
26     }
27 
28 }