From: Gavin Sinclair <gsinclair@...>
Date: 2002-12-02T18:41:23+09:00
Subject: Re: [FAQ] [Revised again] What are the non-alphanumerical symbols in Ruby code?


From: "Martin DeMello" <martindemello@yahoo.com>


> Gavin Sinclair <gsinclair@soyabean.com.au> wrote:
> > ~  <<  >>  &  ^  |
> > [...]
>
> 
> 4. "<<" is also the operator for appending to an array/string in place
>       a = [1,2,3]
>       a += [4,5] # Creates a new array object and assigns it to a
>       a << [4,5] # appends [4,5] directly to the array object a points
>                  # to
> 
> (personally, I use that even more than I do here documents)


Thanks Martin.  I've rearranged that section as well.  It now reads <<EOF


~  <<  >>  &  ^  |

    Binary (bitwise) operators.  "~" returns the bitwise complement of
    the value (~2 is -3); "<<" and ">>" shift the bits of the value
    left and right by the specified number of bits (2 << 2 is 8 >> 2).
    "&", "^", and "|" are bitwise "and" and exclusive and regular "or"
    operators.


<<

    1.  Appends an Array or String in place.

            a = [1,2,3]
            a << 4                # a == [1,2,3,4]

    2.  A "here" document follows, e.g.:

             puts <<EOS
               This is a here document.
             EOS

    3.  "<<" also creates a new class based on a particular object.
        These object-specific classes are called 'singleton classes'.
        In the example below, only the Car object referred to by
        "camaro" will have the method "has_flames?".

             camaro = Car.new
             class << camaro
               def has_flames?
                 true
               end
             end
EOF


I've also added <<EOF

?c

    ?c is the ASCII value of 'c'.

             ?c   # -> 99
             ?"   # -> 34


@  @@

    @var is an instance variable and @@var is a class variable.


EOF


Gavin