• java中instanceof和getClass()的区别分析


    本篇文章介绍了,在java中instanceof和getClass()的区别分析。需要的朋友参考下 class A { } 

    class B extends A { } 

    Object o1 = new A(); 

    Object o2 = new B(); 

    o1 instanceof A => true 

    o1 instanceof B => false 

    o2 instanceof A => true // <================ HERE  o2 instanceof B => true 

    o1.getClass().equals(A.class) => true 

    o1.getClass().equals(B.class) => false 

    o2.getClass().equals(A.class) => false // <===============HERE 

    o2.getClass().equals(B.class) => true 

    getClass() will be useful when you want to make sure your instance is NOT a subclass of the class you are comparing with.

    一个非常完美的equals方法的写法:

    复制代码 代码如下:    public boolean equals(Object otherObject)    {      

    // a quick test to see if the objects are identical     

      if (this == otherObject) return true;

          // must return false if the explicit parameter is null     

      if (otherObject == null) return false;

          // if the classes don't match, they can't be equal     

      if (getClass() != otherObject.getClass()) return false;

          // now we know otherObject is a non-null Employee     

      Employee other = (Employee) otherObject;

          // test whether the fields have identical values      

    return name.equals(other.name) && salary == other.salary && hireDay.equals(other.hireDay);   

    }

    详细出处参考:http://www.jb51.net/article/36114.htm

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  • 原文地址:https://www.cnblogs.com/leihupqrst/p/3572006.html
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