Java code “NumberFormat nf = NumberFormat.getInstance();”

Question

What is the difference between the followings

NumberFormat nf = NumberFormat.getInstance();

and

NumberFormat nf = new NumberFormat()

Why we need to declare NumberFormat object as the first one?

Answer 1

You can't use new NumberFormat() ; as the very first line of the Javadoc notes,

NumberFormat is the abstract base class for all number formats.

You can't directly instantiate an abstract class, so a creational pattern is used.