Ruby Variable Scope
Now that we have covered the basics of variables in Ruby the next task is to explain Ruby variable scope.
What is Variable Scope?
Scope defines where in a program a variable is accessible. Ruby has four types of variable scope, local, global, instance and class. In addition, Ruby has one constant type. Each variable type is declared by using a special character at the start of the variable name as outlined in the following table.
| Name Begins With | Variable Scope |
|---|---|
$ | A global variable |
@ | An instance variable |
[a-z] or _ | A local variable |
[A-Z] | A constant |
@@ | A class variable |
In addition, Ruby has two pseudo-variables which cannot be assigned values. These are nil which is assigned to uninitialized variables and self which refers to the currently executing object.
