The role of instanceof and GetClass () in Java

Beginners are inevitably a little confused about the role of Java instanceof and GetClass (), the following one by one to explain.

Parent Class A:

class A {}

Sub-Class B:

class extends

Constructing objects

New
New

First, instanceof
Demo One:

instanceof
instanceof
instanceof
instanceof

Analysis ==>

Usage:
English: Result = Object instanceof class

English: result = An Instance object instanceof a class name

The instanceof operator in Java is used to indicate at run time whether an object is an instance of a particular class. Instanceof Indicates whether this object is an instance of this particular class or its subclasses by returning a Boolean value.

Summary: S (object) instanceof T (Class) simply, instanceof is to determine whether the object S is an instance of the T class, or a subclass instance of the T class. Second, GetClass
Demo Two:

1, O1.getclass (). Equals (A.class
2, O1.getclass (). Equals (B.class
3, O2.getclass (). Equals (A.class
4, O2.getclass (). Equals (B.class

The analysis ==>getclass method is defined in JDK1.8 as follows:

/**
* Returns the runtime class of this Object
*/
 Public Final native Class<?> getclass ();

Function: Returns the object at the run-time class. GetClass () would be useful if you want to make sure your instance was not a subclass of the class you were comparing with. Three, the difference between instanceof and GetClass 1, the role:

• Instanceof: Used primarily to determine the relationship between objects and classes.
• GetClass: Primarily used to determine the relationship between classes and classes.

Reference: 1, http://www.jb51.net/article/36114.htm

The role of instanceof and GetClass () in Java