The Book of Ruby

Nameless Functions

A Ruby block may be regarded as a sort of nameless function or method, and its most frequent use is to provide a means of iterating over items from a list or range of values. If you have never come across nameless functions, this may sound like gobbledygook. With luck, by the end of this chapter, things will have become a little clearer. Let’s look back at the simple example given earlier. I said a block is like a nameless function. Take this block as an example:

{ |i|
    puts( i )
}

If that were written as a normal Ruby method, it would look something like this:

def aMethod( i )
   puts( i )
end

To call that method three times and pass values from 0 to 2, you might write this:

for i in 0..2
   aMethod( i )
end

When you create a nameless method ...