程式功能：

依次輸入銷售單資料（銷售員編號、銷售產品編號、銷售金額），程式進行相應的統計。

執行結果示例：

程式碼如下：

import java.util.Scanner;

//JHTP Exercise 7.20: Total Sales
//by [email protected]
/**
 * 7.20 (Total Sales) Use a two-dimensional array to solve the following
 * problem: A company has four salespeople (1 to 4) who sell five different
 * products (1 to 5). Once a day, each salesperson passes in a slip for each
 * type of product sold. Each slip contains the following: 
 * a) The salesperson number 
 * b) The product number 
 * c) The total dollar value of that product sold that day 
 * Thus, each salesperson passes in between 0 and 5 sales slips per
 * day. Assume that the information from all the slips for last month is
 * available. Write an application that will read all this information for last
 * month’s sales and summarize the total sales by salesperson and by product.
 * All totals should be stored in the two-dimensional array sales. After
 * processing all the information for last month, display the results in tabular
 * format, with each column representing a salesperson and each row representing
 * a particular product. Cross-total each row to get the total sales of each
 * product for last month. Cross-total each column to get the total sales by
 * salesperson for last month. Your output should include these cross-totals to
 * the right of the totaled rows and to the bottom of the totaled columns.
 */


public class TotalSales {

	 static final int PRODUCTS = 5; //產品數
	 static final int SALESPEOPLE = 4; //銷售員數
	 private static double salesAmountSlip= 0.0;  //單張銷售單金額
	 private static int salesPersonNum= 1;  //銷售員編號
	 private static int productNum= 1;  //銷售員編號
	 private static double[][] salesAmount=  new double[PRODUCTS][SALESPEOPLE];  //彙總銷售額（按產品和銷售員分類）
	 private static Scanner input=new Scanner(System.in);
	 private static int exitFlag = 0;
	 private static double[] salesAmountByProduct = new double [PRODUCTS]; //彙總銷售額（按產品分類）
	 private static double[] salesAmountBySalesPerson = new double [SALESPEOPLE]; //彙總銷售額（按銷售員分類）


public static void main(String[] args)
{

   System.out.println("銷售額月度彙總小程式：");

		
		do{
			System.out.printf("%n請輸入0開始輸入銷售單資料（輸入-1退出）：");
			exitFlag =input.nextInt();
			if(exitFlag ==-1){
				System.out.printf("已退出程式");
				break;
			}
			
			if (exitFlag == 0)
			inputSlip();			
			} while (exitFlag != -1);
		
		input.close(); //結束銷售單錄入
		
		//彙總銷售額（按產品分類）
		for (int i=0; i<PRODUCTS;i++) {
			for (int j=0; j<SALESPEOPLE; j++)
			salesAmountByProduct[i] += salesAmount[i][j];
		}
		
		//彙總銷售額（按銷售員分類）
		for (int i=0; i<SALESPEOPLE;i++) {
			for (int j=0; j<PRODUCTS; j++)
			salesAmountBySalesPerson[i] += salesAmount[j][i];
		}
		
		System.out.println("銷售單彙總資訊：");
		System.out.printf("產品編號\t\t");
		for (int i=0; i<SALESPEOPLE; i++)
			System.out.printf("銷售員%d\t\t",i+1);
		System.out.printf("產品合計%n");
		
		for (int i=0; i<PRODUCTS;i++) {
			System.out.printf("產品%d\t\t", i+1);
			for (int j=0; j<SALESPEOPLE;j++)
				System.out.printf("%.2f\t\t", salesAmount[i][j]);
			System.out.printf("%.2f\t\t%n", salesAmountByProduct[i]);
		}
			
		System.out.printf("銷售員合記\t");
		for (int i=0; i<SALESPEOPLE;i++) {
			System.out.printf("%.2f\t\t", salesAmountBySalesPerson[i]);
		}
}
  
public static void inputSlip() {
	//輸入銷售員編號
	System.out.printf("請輸入銷售員編號（銷售員編號範圍：1 - %d）：", SALESPEOPLE);
	salesPersonNum =input.nextInt();
	while(salesPersonNum <1 || salesPersonNum > SALESPEOPLE) {
		System.out.printf("請輸入銷售員編號（銷售員編號範圍：1 - %d）：", SALESPEOPLE);
	salesPersonNum =input.nextInt();
	}
	
	//輸入產品編號
	System.out.printf("請輸入產品編號（產品編號範圍：1 - %d）：", PRODUCTS);
	productNum =input.nextInt();
	while(productNum <1 || productNum > PRODUCTS) {
		System.out.printf("請輸入有效的產品編號（產品編號範圍：1 - %d）：", PRODUCTS);
		productNum =input.nextInt();
	}
	
	//輸入銷售額
	System.out.printf("請輸入銷售額：");
	salesAmountSlip =input.nextDouble();
	while(salesAmountSlip <0.0) {
		System.out.printf("請輸入有效的金額：");
		salesAmountSlip =input.nextInt();
	}
	
	System.out.println("該銷售單錄入成功！");
	salesAmount[productNum-1][salesPersonNum-1]+=salesAmountSlip;
	

}