A Ruby block may be regarded as a sort of nameless function or method.
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 (a block), variables declared between upright bars such as |i| can be treated like the arguments to a named method. I will refer to these variables as block parameters.
For example:
3.times { |i|
puts( i )
}
The times method of an integer passes values to a block from 0 to the specified integer value minus 1.
So, this:
3.times{ |i| }
is very much like this:
for i in 0..2 aMethod( i ) end
The second example has to call a named method to process the value of i, whereas the first example uses the name-less method (block) to process i.