In Ruby is there a way to overload the initialize constructor?
I tend to do
class Person
def self.new_using_both_names(first_name, last_name)
self.new([first_name, last_name].join(" "))
end
def self.new_using_single_name(single_name)
self.new(single_name)
end
def initialize(name)
@name = name
end
end
But I don't know if this is the best approach.
The answer is both Yes and No.
You can achieve the same result as you can in other languages using a variety of mechanisms including:
- Default values for arguments
- Variable Argument lists (The splat operator)
- Defining your argument as a hash
The actual syntax of the language does not allow you to define a method twice, even if the arguments are different.
Considering the three options above these could be implemented with your example as follows
# As written by @Justice
class Person
def initialize(name, lastName = nil)
name = name + " " + lastName unless lastName.nil?
@name = name
end
end
class Person
def initialize(args)
name = args["name"]
name = name + " " + args["lastName"] unless args["lastName"].nil?
@name = name
end
end
class Person
def initialize(*args)
#Process args (An array)
end
end
You will encounter the second mechanism frequently within Ruby code, particularly within Rails as it offers the best of both worlds and allows for some syntactic sugar to produce pretty code, particularly not having to enclose the passed hash within braces.
This wikibooks link provides some more reading