Wrapper class object creation question

[Radiya Sojitrawala]

Is this correct and if yes how/why? Why would we not need 'new' to allocate memory to d?

Double d = Double.valueOf("3.14");

thanks
radiya

[Sherry Jacob]

Originally posted by Radiya Sojitrawala:
Is this correct and if yes how/why? Why would we not need 'new' to allocate memory to d?

Double d = Double.valueOf("3.14");

thanks
radiya

Hi Radiya,
Well, actually what we are doing is using the inbuilt function, valueOf(), of the Wrapper class Double to convert a String representation of a double number(3.14) back into double.

When we say Double.valueOf("3.14"), it means that we have a String argument "3.14" which we wish to convert into a Double Wrapper Object as 3.14.

This function will return an object of type Double which will be assigned to d. Hence d has to be of type Double too. That's why we do not need the new operator.

[Philip Heller]

In class Double, the valueOf() method is static. If you check the source code, you'll see that the method is just one line:

return new Double(d);

So there's the constructor call you were wondering about.

-- Phil

[Radiya Sojitrawala]

thanks guys