I want to declare all of them
String a = null, b = null, c = null, d = null;
Yep. That's the way to do it.
You could also do
String a, b, c, d; a = b = c = d = null;
The line below however won't compile:
String a = b = c = d = null; // illegal
(Note that if these are member variables, they will be initialized to