Java Question (On abstract classes) (Problem solved)

[Joony]

Ok, so I'm playing with this new concept of "abstract". I made a very simple program that dosen't do much. I have run across an issue, I get a error message when I compile. "cannot resolve symbol" variable c in class french.

public class Test
{
public static void main(String args[])
{
System.out.println("bah");
Donut yum = new French(5);
yum.EatDonut();
}
}

public abstract class Donut
{
int cost;
public Donut(int c)
{
cost = c;
}
public abstract void EatDonut();
}

public class French extends Donut
{
public French(int c)
{
super(c);
}
public void EatDonut()
{
System.out.println("I am eating a French Donut at the cost of" + c);
}
}

 

[notfred]

You should be using "cost" not "c". cost is the instance variable, the scope of "c" is only the constructor.

 

[AbsolutDealage]

Originally posted by: notfred
Nevermind, EatDonut is part of Donut.

bah, just caught that too

 

[FeathersMcGraw]

c is not your member variable, cost is.

 

[Joony]

hmm, so what do I do to fix it?

 

[Ameesh]

you havent decalred a variable called c,

System.out.println("I am eating a French Donut at the cost of" + c); <----- no var named c here in scope

 

[Cerebus451]

Originally posted by: Joony
hmm, so what do I do to fix it?

System.out.println("I am eating a French Donut at the cost of" + cost);

 

[Ameesh]

Originally posted by: Joony
hmm, so what do I do to fix it?

first make cost public or protected and then change c to cost

 

[notfred]

I edited my earlier post, but I'll say it again since a lot of time people don't re-read psots they already read:

You should be using "cost" not "c". cost is the instance variable, the scope of "c" is only the constructor.

Edit: I see I should go back and read things as this has already been solved.

 

[BigJ]

Originally posted by: Ameesh
you havent decalred a variable called c,

System.out.println("I am eating a French Donut at the cost of" + cost);

Look at whats bold

Also, might want to put in "cost of " + cost + " dollars"); You know, just for aesthetic purposes.

 

[sillymofo]

Originally posted by: FeathersMcGraw
c is not your member variable, cost is.

+ cost

 

[FeathersMcGraw]

Originally posted by: Ameesh

first make cost public or protected and then change c to cost

Changing the visibility of cost isn't necessary since all of the classes are in the same package. But I'd make it protected just out of principle.

 

[Joony]

hmm, wow, it worked even without making cost protected...

so by "supering" c in French, it already knows cost from donut?

 

[notfred]

Originally posted by: Joony
hmm, wow, it worked even without making cost protected...

so by "supering" c in French, it already knows cost from donut?

super(c) in French just calls the Donut constructor with c as an argument.

 

[Joony]

Ah, I get it...

You guys are geniuses! Thanks!