From: Rob Biedenharn <Rob@...>
Date: 2008-06-12T06:21:28+09:00
Subject: Re: ||=

On Jun 11, 2008, at 5:12 PM, Martin DeMello wrote:

> On Wed, Jun 11, 2008 at 1:59 PM, Justin To <tekmc@hotmail.com> wrote:
>> what does ||= do?
>
> a ||= b is shorthand for a = a || b
>
> || is the "or" operator - a || b evaluates to a unless a is nil or
> false, in which case it evaluates to b
>
> a ||= b is most commonly used to say "if a hasn't already been set
> (and is therefore nil), set it to b, else leave it alone"
>
> martin


Just to short-circuit the discussion:

a ||= b

is actually implemented as if:

a || a=b

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-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com