b.java

清华大学第二版

public class B {
	public int a = 10;
	private int b = 20;
	protected int c = 30;
	public int getB(){
		return b; }
} 
//public 
class A extends B {
	public int d;
	public void tryVariables() {
		System.out.println(a);	//允许
	//	System.out.println(b);	//不允许
		System.out.println(getB());	//允许
		System.out.println(c);	//允许
	}
}