Difference between xxxValue() methods and casting

[Nidhi Sar]

The xxxValue() methods of numeric wrappers seem to work just like casting.

Please take a look at the following simple program:

 		Float f = 5.9f;
		short s1 = f.shortValue();
		short s2 = (short)5.9f;
		System.out.println(s1 == s2);
   

The last line prints true.

So what is the advantage of providing these methods in Java language?

Thanks,
Nidhi

[Rob Spoor]

The casting was not introduced until Java 5.0, and it implicitly calls xxxValue() in the background.

When you (implicitly or explicitly) cast a Float to a float (or Integer to int etc) the compiler calls floatValue() (intValue() etc). This will give a NullPointerException if the Float (Integer etc) is null.
When you (implicitly or explicitly) cast a float to a Float (or int to Integer etc) the compiler calls valueOf (which is available for all primitive types).

[Nidhi Sar]

Rob,

That is very interesting. Thanks for sharing the info!!

Nidhi

[Ulrika Tingle]

Nidhi Sar wrote:
That is very interesting.

The automatic conversion between primitives and their corresponding wrapper classes is called autoboxing (which was introduced in version 5).