Thread: creating constructor

I have a Machine class but I don't know how to create a constructor which takes owner, price, and belly_star parameters.


main class

//create machines:
 
		Machine star_on = new Machine(fix_it_up, generator.nextInt(10), true);
		Machine star_off = new Machine(fix_it_up, generator.nextInt(10), false);

Machine class

public class Machine 
{
	boolean belly_star;  //whether the machine changes the star or not
	int price;
	int counter;
	Chappie owner;
 
 
	/**
	 * if belly star is true, and sneetch has no star, put on a star
	 * 
	 * @return true if the machine is successful, false otherwise
	 */
	boolean run(Sneetch s)
	{
		if(s.money<price)
		{
			return false;
		}
 
		if(s.is_starred!=belly_star)
		{
			s.changeStar();
			s.spendMoney(price);
			owner.collectMoney(price);
			return true;
		}
 
		return false;
	}
	/**
	 * 
	 * @param raise
	 * @return price
	 */
	public void priceHike(double raise)
	{
		price = price*(1 + raise);
 
	}
 
 
}

You code them essentially just like a method; however you have no return type and the "method name" is the class name.
So in your case it would simply be

public Machine(//parameters go here) {
     //Other operations in here
}

It's really pretty straight forward

I'm not sure which one fix_it_up is, but your constructor should look something like this

public Machine(Fix_It_Up_Class fix_it_up, int number, boolean b)
{


}

Also, maybe I'm missing something, but I noticed another possible problem.

price = price*(1 + raise);

price is going to be a double since you have a doube, raise I think, in there.

Also, even if price were a double, it would seem you never set it to something other than 0 to start with.

That would mean that price would be 0.0 (if it was double that is)

and

0.0 (1 + raise) will always be equal to 0.0 no matter what raise is.

s.spendMoney(price);
owner.collectMoney(price);

Will be spending 0.0 and your owner won't be getting paid anything either.

Also long as s.money is non-negative, it's always going to skip that first if statement.

if(s.is_starred!=belly_star)

belly_star is never initialized.

By any chance is belly_star the third parameter to your constructor?

The price would possibly instantiated upon creation of the constructor is what I would guess.