Re: Functions with optional parameters
- To: mathgroup at smc.vnet.net
- Subject: [mg51963] Re: Functions with optional parameters
- From: Bill Rowe <readnewsciv at earthlink.net>
- Date: Fri, 5 Nov 2004 02:19:57 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
On 11/4/04 at 1:49 AM, gregory.lypny at videotron.ca (Gregory Lypny) wrote: >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. In this particular case, it might be simpler/faster to give c a default value of 0, i.e., addThem[a_,b_,c_:0]:=a+b+c addThem[1, 2] 3 addThem[1, 2, 3] 6 My guess is adding 0 is faster than testing to see whether c is empty and deciding which branch to take -- To reply via email subtract one hundred and four