Re: help with new symbols (or pointers)

*To*: mathgroup at smc.vnet.net*Subject*: [mg92426] Re: help with new symbols (or pointers)*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Tue, 30 Sep 2008 21:50:43 -0400 (EDT)*Organization*: The Open University, Milton Keynes, UK*References*: <gbt2t4$lfo$1@smc.vnet.net>

ag wrote: > Hi, > > I want to create new symbols inside a module & assign them values=85 > > e.g. something like: Symbol[=93x=94<>"num"] = 5 > It is not working=85 > > The problem is that I dont know how many symbols I would need (it > could be 5, 50 or 5000)... So I cannot do something like: > Symbol["x"<>"1"]; > x1=5; > > Is there anything in Mathematica which is like pointers in C > (something which would assign a value to a given location in memory)? > > Any help would be appreciated! The following should help: Do[Set[Evaluate[Symbol["var" <> ToString[num]]], 2 num], {num, 3}] Do[Print[Symbol["var" <> ToString[num]]], {num, 3}] 2 4 6 Note that the assignment operator '=' is written in fullform Set and it has the attribute *HoldFirst* that prevents the immediate evaluation of its first argument (so we force it thanks to the function *Evaluate*). Also, *ToString* transforms an expression (a number in our case) into a string of characters. Regards, -- Jean-Marc