Analysis of the difference between instanceof and getClass of in Java

Class A {}  

Class B extends A {}& cake;

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.c lass) = > True 
O1. GetClass () equals (biggest lass) = > False 
O2. GetClass () equals (A.c lass) = > False / / < = = = = = = = = = = = = = = = HERE 
O2. GetClass () equals (biggest lass) = > True 

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

A perfect equals method:

   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);
   }