What does the “yield” keyword do in Ruby?

Question

I encountered the following Ruby code:

class MyClass
    attr_accessor :items
    ...
    def each
        @items.each{|item| yield item}
    end
    ...
end         


        

Answer 1

A Ruby method that receives a code block invokes it by calling it with the yield keyword. It can be used to iterate over a list but it is not a iterator like what you find in other some other languages.

Here is a good explanation that explains it better than I would ever be able to.

Answer 2

As cpm said its taking the block and executing it

Simple example:

def my_method
  yield
end


my_method do
  puts "Testing yield"
end

Testing yield
=> nil