Learning Try-Catch

Question

I'm a Java beginner so please bear with me

static int load = 100;
static int greet;

public void loadDeduct(int cLoad, int c){
    int balance;
    balance = cLoad - 7;
    System.out.println("Your balance: " + balance);
}

public void loadDeduct(int tLoad){
    int balance;
    balance = tLoad - 1;
    System.out.println("Your balance is: " + balance);
}

public static void main (String [] args){
    int choice;
    Scanner scan = new Scanner(System.in);

    System.out.println("I'm a cellphone, what do you want to do?");
    System.out.println("Press 1 to send SMS / Press 2 to Call");

    choice = scan.nextInt();

    CellphoneLoad N95 = new CellphoneLoad();

    if (choice == 1){
        N95.loadDeduct(load);
    }else if (choice == 2){
        N95.loadDeduct(load, greet);
    }else{
        System.out.println("Invalid Option!!!");
    }

How do I implement the exception handling with this program? I'm not quite sure how to use the catch block as we weren't taught yet about the whole exceptions thing. It was just an exercise we were asked to do. I want to replace the if else statements with a try-catch blocks... is that possible?

Answer 1

One important principle to consider with exceptions in Java is that there are two types: 1. Runtime 2. Typed/explicit (for lack of a better word)

Runtime exceptions should be thrown when there is a programming error and generally they should not be caught unless you are catching at the top level to report an error.

Typed/Explicit exceptions are decorated on method calls and should be there so the caller can take some action on them.

In the case of the code above, there isn't really a place that feels like it should use exception handling.

And as Patrick pointed out, you don't generally want to use exceptions for flow control.