On 12 May 2007, at 11:37, Sebastian Hungerecker wrote:

> Human Dunnil wrote:
>> I was looking at one of the Ruby Quiz solutions (Countdown) in Ruby
>> Quiz book, it uses << operator, which I don't understand!
>
> If you're looking at the same code as I am, the << isn't used as  
> the shift
> operator. It's used to add items to an array. << only acts as shift  
> operator
> on numbers.

The << operator has many different uses:

- In an Array it is used to append (push) an object into a given array
- In a Fixnum and a Bignum object (i.e integers) it shifts the number  
bits to the left
- In an IO object it will write the object (as a string) to the IO  
object.
- In a String it will append the object (to_s) to the String (if the  
object is a Fixnum between 0 and 255 it will convert it to the  
character representation before appending it)

I hope this helps...

Cheers,

Enrique Comba Riepenhausen