The difference analysis of instanceof and GetClass () in Java _java

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 () would be useful if you are want to make sure your instance are not a subclass of the class for you are comparing with.

A very perfect method of equals:

Copy Code code as follows:

public boolean equals (Object otherobject)
{
A quick test to the 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);
}