Returning a value from one method to another to be used in the output-CodePudding

I can't figure out how to return the value of finalCost to the main method and have it printed.

import java.util.*;

public class PhonePlan {
    private static double basecost = 8.5;
    private static double rate = 0.35;
    private static double discount = 0.15;

    public static void main(String[] args) {
        //Scan input for downloadLimit
        Scanner scan = new Scanner(System.in);
        System.out.print("Enter the download limit in GB: ");
        int downloadLimit = scan.nextInt();
        // Call other method
        calcMonthlyCharge(downloadLimit);

        System.out.println("Plan monthly cost: "   calcMonthlyCharge(finalCost));
    }

    public static double calcMonthlyCharge(double downloadLimit) {
        // Calculate final cost
        double fullCost = downloadLimit * rate   basecost;
        double planDiscount = fullCost * discount;
        double finalCost = fullCost - planDiscount;
        return finalCost;
    }
}

Specifically, I can't find how to use the returned value in the "println" line.

    System.out.println("Plan monthly cost: "   calcMonthlyCharge(finalCost) ); 
} 
public static double calcMonthlyCharge(double downloadLimit) { 
    // Calculate final cost 
    double fullCost = downloadLimit * rate   basecost; 
    double planDiscount = fullCost * discount; 
    double finalCost = fullCost - planDiscount; 
    return finalCost;
}

CodePudding user response：

You call calcMonthlyCharge(downloadLimit),but don't store the returnvalue.

When you call System.out.println("Plan monthly cost: " calcMonthlyCharge(finalCost) ); It is unknown what finalcost is, this is a variable which only exist in the scope of calcMonthlyCharge

Either store the returnvalue of calcMonthlyCharge(downloadLimit) and reuse the value to print, or use calcMonthlyCharge(downloadLimit) in your println with downloadLimit as parameter to get a new returnvalue.