java - 为什么价格打印两次？

Question

我的代码:

package ecommerceapp;

import java.util.Scanner;

public class ECommerceApp {
public static void main(String[] args) {
    String productsCatalog = " ";
    //double price = getPrice();
    bannerPrinter();
    productsBuilder();
    boolean exists = getOrder(productsCatalog);

    if (exists == true) {
        double salesTotal = 0;
        printTotal(salesTotal);
    } else {
        System.out.println("The product not found.");
    }
    //double price = 0;
    //double tax = getTax(price);

    //getTotal(price, tax);
}

public static void bannerPrinter() {
    System.out.println("******************************************");
    System.out.println("====== Welcome to my eCommerce app! ======");
    System.out.println("******************************************");
}

public static String productsBuilder() {
    String productsCatalog = "Desk      Table     Pen       ";
    return productsCatalog;
}

public static boolean getOrder(String productsCatalog) {
    String userProduct;
    boolean exists = true;
    Scanner scnr = new Scanner(System.in);
    System.out.print("Please enter a product name: ");
    userProduct = scnr.nextLine();
    if (productsBuilder().toLowerCase().contains(userProduct.toLowerCase())) {
        exists = true;
        System.out.println(exists);
    } else {
        exists = false;
        System.out.println(exists);
    }
    return exists;
}

public static double getPrice() {
    double price = 1 + Math.random() * 99;
    price = Math.round(price * 100.0) / 100.0;
    System.out.println("Price is: " + price);
    return price;
}

public static double getTax(double price) {
    double tax = (0.1 * getPrice());
    tax = Math.round(tax * 100.0) / 100.0;
    System.out.println("Tax is: " + tax);
    return tax;
}

public static double getTotal(double price, double tax) {
    double salesTotal = getPrice() + getTax(price);
    return salesTotal;
}

public static void printTotal(double salesTotal) {
    double price = 0;
    double tax = 0;
    System.out.printf("Your sale total is: $%.2f", getTotal(price, tax));
    System.out.println();
}

}

为什么我的输出将价格打印两次？

<小时/>

====== 欢迎使用我的电子商务应用程序! ======

<小时/>

请输入产品名称:desk

正确

价格为:64.43

价格为:85.07

税费为:8.51

您的销售总额为:72.94 美元

构建成功(总时间:3秒)

当我从 getPrice 和 getTax 中删除 System.out.println 时，这是我的输出

<小时/>

====== 欢迎使用我的电子商务应用程序! ======

<小时/>

请输入产品名称:desk

正确

税费为:8.6

您的销售总额为:38.60 美元

Answer 1

因为您正在打印 getPrice 的结果。 getPrice 本身是打印价格，因此您的程序会打印价格两次。删除 getPrice block 中的“System.out.println”函数。