Strange behaviour with Object.intValue()

Question

I am struggling with a problem, which I can\'t understand why it doesn\'t work. How do I pass a variable through the double obj and convert to int

Answer 1

You're in the top snippet, trying to assign a Double object to a primitive type like this.

double doubleObj=new Double( doublehelpermethod);

which would of course work because of unboxing (converting a wrapper type to it's equivalent primitive type) but what problem you're facing is dereferencing doublehelpermethod.

doublehelpermethod.intValue()

is not possible because doublehelpermethod is a primitive type variable and can not be associated using a dot . See... AutoBoxing

Answer 2

The double is a primitive type, while the Double is a regular Java class. You cannot call a method on a primitive type. The intValue() method is however available on the Double, as shown in the javadoc

Some more reading on those primitive types can be found here