Doubt about private modifier

[Marianne Rivera]

Hi,

I am in doubt in what I am learning.

 public class GoodDog{
	private int size;
	
	public int getSize() {
		return size;
	}
	
	public void setSize(int s) {
		size = s;
	}
	
	void bark() {
		if (size > 60){
			System.out.println("Wooof! Wooof!");
		}else if (size > 14){
			System.out.println("Ruff! Ruff!");
		}else{
			System.out.println("Yip! Yip!");
		}
	}
	
	public static void main (String[] args){
		GoodDog dog = new GoodDog();
		dog.size = 0;  //expecting compiler error
		//dog.bark();
	}
}   

I thought setting a private access modifier will prevent my instance variable from being set incorrectly.

But when I compile this class using javac, I encounter no error. I thought there will be an error in the head first java book.

I am having a hard time figuring how to learn java.. Please help..

[Moojid Hamid]

Since this main method is inside the same class it can access its private variables (and methods).

[Vijitha Kumara]

Marianne Rivera wrote:I thought setting a private access modifier will prevent my instance variable from being set incorrectly.
But when I compile this class using javac, I encounter no error.

That's allowed only within the same class as the private variable. No one can access it directly outside the class.

I thought there will be an error in the head first java book.
I am having a hard time figuring how to learn java..

You are with the right material. Just work out the things in the book.

[Marianne Rivera]

Hi,

So thats the reason. Now I understand why the book is always talking about the TestDrive Class though I am not yet sure about the keyword static upto now. Maybe later the book will explain it to me.. hopefully..

Thanks to both of you.