private int has to be 10, 20 or 30-CodePudding

i'm trying to make a simple pizza assignment. i want to make it unable to make a pizza if the price is not 10, 20 or 30

public static void main(String[] args) {
        Pizza tonno = new Pizza(3); //this should not be possible 
        Pizza tonno = new Pizza(10); //this should be possible

    }


public class Pizza{
        private int Price;

        public Pizza(int price) {
        Price = price;
        
    }

    public int getPrice() {
        return Price;
    }

    public void setPrice(int price) {
       
        Price = price;
    }

}

if the given parameter is not 10, 20 or 30 the program should not make the new pizza. So if i make a new pizza and i give it the price 3 i don't want it to work. the price of the pizza should be 10, 20 or 30 nothing else.

how do i do this?

CodePudding user response：

This should work for you. This way anything outside the scope of Pizza is restricted to using the constructor that requires a 'PizzaType'.

Please note: I am assuming that the setPrice() method has some purpose, that is why I only used the enum in the constructor, and not just as a field of Pizza.

public class Pizza{

    public enum PizzaType{
        SMALL(10), MEDIUM(20), LARGE(30);
        
        int price;
        
        PizzaType(int price){
            this.price = price;
        }
    }

    private int Price;
    private Pizza(int price) {
        Price = price;
        
    }
    
    public Pizza(PizzaType p){
        this(p.price);
    }

    public int getPrice() {
        return Price;
    }

    public void setPrice(int price) {
        Price = price;
    }

}