Types of Variables in Ruby
There are 4 different types of variables in Ruby. They are :
- Local Variables
- Class Variables
- Instance Variables
- Global Variables
| Local | Global | Instance | Class | |
|---|---|---|---|---|
| Scope | Only within the block or a function | Throughout the program | Limited to one particular instance of a class | Limited to the class that they are defined in |
| Naming | Local variables begin with a lowercase letter or _(underscore) | Global variables begin with $ | Instance variables begin with @ | Class variables begin with @@ |
| Initialization | Not necessary to initialize. Using uninitialized local variable is interpreted as call to a method that has no arguments. | Not necessary to initialize. Uninitialized global variables have nil value. | Not necessary to initialize. Uninitialized instance variables have nil value. | Must be initialized before they are used. Using uninitialized class variable results in error. |