From: Phrogz <phrogz@...>
Date: 2009-12-09T06:05:20+09:00
Subject: Re: Example Ruby Code

On Dec 8, 10:30 am, Christopher Davidson <davidson...@gmail.com>
wrote:
> Can anybody explain how this code actually works in simple terms if
> possible :).
>
> def animals
>   yield "Tiger"
>   yield "Giraffe"
> end
>
> animals { |x| puts "Hello, #{x}" }

In case you know JavaScript, and are comfortable with functions as
first-class values, you might write this as:

function animals( doSomething )
{
  doSomething( "Tiger"   );
  doSomething( "Giraffe" );
}

animals( function(x){ console.log( "Hello, %s", x ) } );

//or more explicitly
var myLogger = function(x){
  console.log( "Hello, %s", x );
}
animals( myLogger );


As Robert said, the notation for "blocks" in Ruby defines an anonymous
callback, and yield invokes it. As Bertram points out, there is an
alternate way of defining a method so that the block is explicitly
associated with a variable.