Re: A set of several questions

*To*: mathgroup at smc.vnet.net*Subject*: [mg90173] Re: A set of several questions*From*: Steven Siew <stevensiew2 at gmail.com>*Date*: Tue, 1 Jul 2008 07:00:53 -0400 (EDT)*References*: <g451va$pq7$1@smc.vnet.net> <g47l5a$t98$1@smc.vnet.net>

On Jun 29, 7:37 pm, David Bailey <dave at Remove_Thisdbailey.co.uk> wrote: > Let me concentrate on question 5. One way to effectively obtain the > functionality of structures, is to pick a head that has no meaning and > use it to make a structure: > > myStruct[a,b,4,e] > > Such an object could be passed to a function defined as: > > f[s_,x_]:= ....... > > or, preferably > > f[s_myStruct,x_]:= ............. > > The latter form will only accept a myStruct object as its first > argument, and is thus preferable. > > To extract the fourth item of the structure (say), you could write > Extract[s,4]. There is a much easier way to extract the fourth item. Just use s=myStruct[a,b,4,e] s[[4]] Steven Siew