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

As a newbie, looking through a number of the answers confused me until I hit Abhi's answer.

the yield command pauses executing the code in the method, and instead passes control back to the block of code that called it, executes that code, and then continues executing the rest of the method after that. Here's an example that clarified it for me:

def hello
    puts "hello"
    yield 
    puts "world"
end

hello do
    puts "there"
end 

Output:

hello

there

world