How to Use alias and alias_method in Ruby

Contents
In this article, you will learn how to use alias and alias_method in Ruby.
Using alias and alias_method
In Ruby, alias and alias_method are two methods that are used to give an alternative name to an existing method or to create a new method with the same implementation as an existing method.
Here’s how to use them:
alias keyword
The alias keyword is used to create a new name for an existing method. Its syntax is:
alias new_name old_name
For example, if you want to give the method say_hello an alternative name greet, you can use alias as follows:
def say_hello
puts "Hello!"
end
alias greet say_hello
greet # Output: Hello!
alias_method method
The alias_method method is similar to the alias keyword, but it can be used to alias a method from any class, not just the current one. Its syntax is:
alias_method :new_name, :old_name
For example, if you have a class Person with a method introduce and you want to give it an alternative name greet, you can use alias_method as follows:
class Person
def introduce
puts "Hello, my name is #{name}."
end
alias_method :greet, :introduce
end
person = Person.new
person.greet # Output: Hello, my name is .
Note that alias and alias_method are different in that alias can only be used within the context of the current class or module, whereas alias_method can be used to alias methods from any class. Additionally, alias_method is more flexible in that it can be used to alias private methods, whereas alias cannot.