assign Integer type to int

Question

Is there any problem (Run Time of course) in assigning Integer to int ?

int x= Integer.class.cast(parameters.get("PO_PAGE_CNT"));

As Integer is the parent class and int is the instance, I think maybe in some cases I get ClassCastException or other type of Exception at run time. Is it right?

Answer 1

Assuming that parameters.get("PO_PAGE_CNT") returns an instance of Integer , there is no problem with this assignment.

It would be more readable to simply write :

int x = (Integer) parameters.get("PO_PAGE_CNT");

An int can always be assigned to Integer (Boxing) and vice versa (Unboxing).

Answer 2

no problem. There is concept called boxing and unboxing. you can follow this link .

Answer 3

No, there is no problem. Integer values are automatically unboxed to int values and vice versa.

There is one exception, though. If parameters.get("PO_PAGE_CNT") returns null , you'll get a NullPointerException , since there is no int equivalent to null .

Answer 4

There is no problem. You are boxing and unboxing Integer. And there will be no ClassCastException if you are unboxing Integer to int