classinheritance.java

来自「这是《Java 2 简明教程(第2版)》一书配套的源代码。」· Java 代码 · 共 37 行

class A
{
  int a1=1;
  public int a2=2;
  protected int a3=3;
  private int a4=4;
  int geta4()
  {
    return a4;
  }
}

class B extends A
{
  int b=5;
  int sum()
  {
  return a1+a2+a3+geta4()+b;
  }
}

class ClassInheritance
{
  public static void main(String args[])
  {
    A aa= new A();
   System.out.println("A:"+aa.a1+"\t"+aa.a2+"\t"+aa.a3+"\t"+aa.geta4());
   
    B bb= new B();
    System.out.println("B:"+bb.a1+"\t"+bb.a2+"\t"+bb.a3+"\t"+bb.geta4()+"\t"+bb.b+"\t" +bb.sum());
  }

}