From: dblack@...
Date: 2007-01-14T23:23:43+09:00
Subject: Re: Question about Array's size instance method

Hi --

On Sun, 14 Jan 2007, Timothy Hunter wrote:

> Matt Gretton wrote:
>> Hello all,
>> 
>> I have a quick question regarding the way the size instance method works
>> for Arrays.
>> 
>> When an array is asked for its size multiple times in a piece of code
>> (say a method). Which of the following happens?
>> 
>> a) The size is calculated every time the array is asked for it.
>> b) The size is assigned to an instance variable the first time it is
>> calculated   and then returned when the array is subsequently asked for
>> its size.
>> 
>> Any reply to this question would be gladly received.
>> 
>> Thanks in advance.
>> 
>> Matt.
>>
>> 
> Ruby always knows the current size of the array. It doesn't have to be 
> calculated on demand.

I'll just add, in case it helps with future understanding of something
similar, that I don't think Ruby ever initializes an instance variable
for you, without your specifically doing it (or implicitly, in the
case of attr_*-generated methods).


David

-- 
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