why is price being printed twice?

Question

My Code:

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();
}

}

Why is my output printing the price twice?

---

====== Welcome to my eCommerce app! ======

---

Please enter a product name: desk

true

Price is: 64.43

Price is: 85.07

Tax is: 8.51

Your sale total is: $72.94

BUILD SUCCESSFUL (total time: 3 seconds)

When I remove System.out.println from both getPrice and getTax, this is my output

---

====== Welcome to my eCommerce app! ======

---

Please enter a product name: desk

true

Tax is: 8.6

Your sale total is: $38.60

Answer 1

because you are printing the result of getPrice. and getPrice itself is printing price so as a result, your program prints price twice. delete the "System.out.println" function in your getPrice block.

Answer 2

因为您在getTax()和getTotal()中都getTax()了显示价格的getPrice() getTotal() 。

Answer 3

When you call getTotal (Inside printTotal) you are calling getPrice which in itself has

System.out.println("Price is: " + price);

and as a result of this when you then call the getTax you are calling the getPrice again

double tax = (0.1 * getPrice());

which then calls the println and that is why it prints twice.