Integer class

[Nazma Panjwani]

Hi,
If you instantiate the Integer class passing in a certain value such as 60...is it possible to change that value to something else later on?
Thanks

[Rob Spoor]

The object itself can never change anymore. You cannot modify any of its fields, nor call any method that changes it. You can still change the value the reference points to. For instance:

Integer i = Integer.valueOf(4);
i = Integer.valueOf(5);

[Marcos Stoppa]

At Java 5, was added the called autoboxing. With autoboxing you can create a new Wrapper object, with a new value, without manually boxing and unboxing it.

Integer i = 1; // Ok
i = i + 1;     // Ok, a new Integer is created and assigned to i reference variable, with a value of 2.
   

[Rob Spoor]

I know, but I set up my Eclipse to warn against it. Autoboxing is not a problem, but autounboxing is a potential NullPointerException waiting to happen if you're not careful. Because you're not dereferencing anything yourself it will be harder to find the culprit.

[Nazma Panjwani]

Marcos Stoppa wrote:At Java 5, was added the called autoboxing. With autoboxing you can create a new Wrapper object, with a new value, without manually boxing and unboxing it.

Integer i = 1; // Ok
Integer i = i + 1; // Ok, a new Integer is created and assigned to i reference variable, with a value of 2.
   

Hey,

It doesn't work, since i is already defined......

[Marcos Stoppa]

Oooops, sorry. My fault.

The correct is:

    Integer i = 1; // Ok
    i = i + 1;     // Ok, a new Integer is created and assigned to i reference variable, with a value of 2.

Thanks Nazma!