Difference between null and empty (“”) Java String

Question

What is the difference between null and the \"\" (empty string)?

I have written some simple code:

String a = \"\";
String b         


        

Answer 1

String s = "";
s.length();

String s = null;
s.length();

A reference to an empty string "" points to an object in the heap - so you can call methods on it.

But a reference pointing to null has no object to point in the heap and thus you'll get a NullPointerException.