How to check null on StringBuilder?

Question

I want to check for null or empty specifically in my code. Does empty and null are same for StringBuilder in Java?

For example:

StringBuilde         


        

Answer 1

No. empty means, that there are no characters in the StringBuilder. null means that there is no StringBuilder object at all.

A variable is only null if it has a reference type (for example String, StringBuilder, Set, as a thumbrule: all capitalized types) and it is not initialised yet or has been set explicitly to null.