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

According to my understanding yield executes code from block.

def name
    puts "A yield will be called with id of 12"
    yield 12
    puts "A yield will be called with id of 14"
    yield 14
end


name {|i| puts "I am called by yield name #{i}"}

Output:

A yield will be called with id of 12

I am called by yield name 12

A yield will be called with id of 14

I am called by yield name 14

How yield works?

So when the name function runs wherever yield comes the block code runs. Which is name {|i| puts "I am called by yield name #{i}"}

You can see that there is a word yield 12 yield runs the code inside block passing 12 as value of i.

Here is a game example for it:

def load_game
    puts "Loading"

    yield

end


load_game { puts "Game loaded" }

This will print game loaded right after printing loading:

Loading

Game Loaded