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. |
