/*Object:是所有對(duì)象的直接后者間接父類，傳說中的上帝。該類中定義的肯定是所有對(duì)象都具備的功能。Object類中已經(jīng)提供了對(duì)對(duì)象是否相同的比較方法。如果自定義類中也有比較相同的功能，沒有必要重新定義。只要沿襲父類中的功能，建立自己特有比較內(nèi)容即可。這就是覆蓋。*/class Demo //extends Object{  private int num;  Demo(int num)  {    this.num = num;  }    public boolean equals(Object obj)//Object obj = new Demo();  {    if(!(obj instanceof Demo))      return false;    Demo d = (Demo)obj;    return this.num == d.num;  }    /*  public boolean compare(Demo d)  {    return this.num==d.num;  }  */  public String toString()  {    return "demo:"+num;  }}class Person {}class ObjectDemo {  public static void main(String[] args)   {    Demo d1 = new Demo(4);    System.out.println(d1);//輸出語句打印對(duì)象時(shí)，會(huì)自動(dòng)調(diào)用對(duì)象的toString方法。打印對(duì)象的字符串表現(xiàn)形式。    Demo d2 = new Demo(7);    System.out.println(d2.toString());    //Demo d2 = new Demo(5);    //Class c = d1.getClass();////    System.out.println(c.getName());//    System.out.println(c.getName()+"@@"+Integer.toHexString(d1.hashCode()));//    System.out.println(d1.toString());    //Person p = new Person();    ///System.out.println(d1.equals(p));  }}