What is the difference between @@ and @ in Ruby? [duplicate]

Question

I just started learning Ruby and I have been unable to find a good explanation on what is the difference between @@ and @ in terms of class variables. If anyone can provide a basic intuitive example, that would be really great. Also are they interchangeable?

Answer 1

A variable prefixed with @@ is a class variable and one prefixed with @ is an instance variable. A great description can be found in this answer: https://stackoverflow.com/a/5890199/1181886

Answer 2

@ before a variable name : instance variable (one per instance)

@@ before a variable name : static variable (one per class)