How can I correct this code, so it can work?-CodePudding

import java.util.Scanner; // Needed to make Scanner available

public static int age()
{
    int age;
    Scanner scanner = new Scanner(System.in);
    System.out.println("How old are you? ");
    age = Integer.parseInt(scanner.nextLine());
    return age;
}

age();

public static void yesornodisability()
{
    String disabled;
    Scanner scanner = new Scanner(System.in);
    System.out.println("Are you registered disabled(Yes / No)? ");
    disabled = scanner.nextLine();
    return;
}

yesornodisability();

public static int total()
{
    int total;
    total = 10;
    return total;
}

total();

public static void swimmingprice()
{
    if (age()<=18);{
    total() = total()/2};
    
    else if (age()>=65);{
        total()=total()-3};
    
    else if (yesornodisability().equals("Yes");{
        total() = total()-4};
    
    System.out.println("The swimming price for you is " total() " pounds.");
}

I am asking two sets of questions the first question is asking there age, second question is asking if they are registered disabled. Then using both results I put them in a if statement. As if they are younger than 18 they get 50% discount, if they are registered disable they get 4 pounds discount. My inputs are working, but when I put them in the if statement they are class it expected and else without if error.

CodePudding user response：

First problem, don't write these isolated statements in the class body yesornodisability();, age(); and total(); . I doubt they compile.

Second store intermediate values. Since age() asks to input the age each time, it will be very inconvenient. Plus the user might enter different values.

int userAge = age();
int totalCost = total();
boolean disability = yesornodisability();

I also made a variable for total() because you want to update the value, and a variable yesornodisability() so the question gets asked immediately.

Your if statements have valid but incorrect syntax. You need to remove the semi-colons after them otherwise they won't have a body and the statement following will always be executed.

CodePudding user response：

Consider calling your methods from within the main method:

import java.math.BigDecimal;
import java.util.Scanner;

public class AnonymosSwimmingPriceCalculator {

    private static final int MAX_YOUTH_AGE = 18;
    private static final BigDecimal YOUTH_DISCOUNT_PERCENT = BigDecimal.valueOf(0.5); // 50%.
    private static final BigDecimal DISABLED_DISCOUNT_DOLLARS = BigDecimal.valueOf(4);  // $4.

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int age = getPositiveIntegerInput("How old are you? ", scanner);
        boolean isDisabled = getYesOrNoInput("Are you registered disabled (Yes/No)? ", scanner);
        BigDecimal baseSwimmingPrice = new BigDecimal(10);
        BigDecimal actualSwimmingPrice = getSwimmingPrice(baseSwimmingPrice, age, isDisabled);
        System.out.printf("The swimming price for you is %.2f pounds.%n", actualSwimmingPrice);
    }

    private static BigDecimal getSwimmingPrice(BigDecimal baseSwimmingPrice, int age, boolean isDisabled) {
        BigDecimal actualSwimmingPrice = baseSwimmingPrice;
        if (age <= MAX_YOUTH_AGE) {
            actualSwimmingPrice = actualSwimmingPrice.multiply(YOUTH_DISCOUNT_PERCENT);
        }
        if (isDisabled) {
            actualSwimmingPrice = actualSwimmingPrice.subtract(DISABLED_DISCOUNT_DOLLARS);
        }
        return actualSwimmingPrice;
    }

    public static int getIntegerInput(String prompt, Scanner scanner) {
        System.out.print(prompt);
        int validInteger = -1;
        while (scanner.hasNext()) {
            if (scanner.hasNextInt()) {
                validInteger = scanner.nextInt();
                break;
            } else {
                System.out.println("Error: Invalid input, must be integer, try again...");
                System.out.print(prompt);
                scanner.next();
            }
        }
        return validInteger;
    }

    public static int getPositiveIntegerInput(String prompt, Scanner scanner) {
        int num = getIntegerInput(prompt, scanner);
        while (num <= 0) {
            System.out.println("Error: Integer must be positive.");
            num = getIntegerInput(prompt, scanner);
        }
        return num;
    }

    public static boolean getYesOrNoInput(String prompt, Scanner scanner) {
        System.out.print(prompt);
        String input = scanner.nextLine().toLowerCase();
        while (!input.equals("yes") && !input.equals("no")) {
            input = scanner.nextLine().toLowerCase();
        }
        return input.equals("yes");
    }

}

Example Usage 1:

How old are you? 25
Are you registered disabled (Yes/No)? No
The swimming price for you is 10.00 pounds.

Example Usage 2:

How old are you? 18
Are you registered disabled (Yes/No)? Yes
The swimming price for you is 1.00 pounds.