Am trying to parse String intto Double, is it possible?

Question

Please is this being smart or stupid..i tried to return a String in a method of type double..

 public double withdrawCash()
 {
    if (amounts == 20)
    {
        totalWithdrawal = BALANCE - 20;
        return totalWithdrawal;
    }else if (amounts == 40){
        totalWithdrawal = BALANCE - 40;
        return totalWithdrawal;
    }else if (amounts == 60){
        totalWithdrawal = BALANCE - 60;
        return totalWithdrawal;
    }else if (amounts == 100){
        totalWithdrawal = BALANCE - 100;
        return totalWithdrawal;
    }else if (amounts == 200){
        totalWithdrawal = BALANCE - 200;
        return totalWithdrawal;
    }
    else{ //this where i tried to be smart or stupid...just learning..help!!!
        String complainWithdrawal = "Please, you need to select appropriate amount";
        double showWithdrawal = Double.parseDouble(complainWithdrawal);
        return showWithdrawal;
    } 
}

Kindly advice me on the ideal solution

Answer 1

    String bla = "12.25";

    double showWithdrawal = 0;

    try {
        showWithdrawal = Double.parseDouble(bla);
    } catch (Exception e) {
        e.getMessage();
    }

    System.out.println(showWithdrawal);

You can do like that

Answer 2

double showWithdrawal = Double.parseDouble(complainWithdrawal);

This line will throw an error. You cannot return a String as a double. Instead, you can replace it with:

throw new InputMismatchException("Please, you need to select appropriate amount.");

And catch it outside like this:

try {
    withdrawCash();
} catch (InputMismatchException e) {
    System.out.println("Error withdrawing cash: " + e);
}

Answer 3

Can I also suggest that for money you don't use double. Take a look at BigDecimal as well. There are a lot of issues you will run into down the road using double for monetary values.