Re: Functions with optional parameters
- To: mathgroup at smc.vnet.net
- Subject: [mg51961] Re: [mg51886] Functions with optional parameters
- From: Tomas Garza <tgarza01 at prodigy.net.mx>
- Date: Fri, 5 Nov 2004 02:19:50 -0500 (EST)
- References: <200411040649.BAA18109@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
I'm not sure I get your question. If a, b, c, are numbers, then c cannot be
empty.. It may be zero. Of course, if they are numbers, you may simply use
In[13]:=
addThem[a_, b_, c_] := Plus @@ {a, b, c}
and it doesn't matter whether c is zero or not. In this problem, it is -
IMO - unnecesary to define the function addThem, since it takes the same
amount of typing as simply Plus@@. If you wish to use optional parameters in
other situations, take a look at the Help browser under Optional.
Tomas Garza
Mexico City
----- Original Message -----
From: "Gregory Lypny" <gregory.lypny at videotron.ca>
To: mathgroup at smc.vnet.net
Subject: [mg51961] [mg51886] Functions with optional parameters
> Hello everyone,
>
> How can I create functions with optional parameters? For example, a
> simple function to add two or three numbers:
>
> addThem[a_,b_,c_]:=If[c is not empty, Sum[a,b,c],Sum[a,b]]
>
> I'm not sure of the proper syntax to test whether c is null or empty.
>
> Greg
>
>
- References:
- Functions with optional parameters
- From: Gregory Lypny <gregory.lypny@videotron.ca>
- Functions with optional parameters