Re: Question about UpSet vs SetDelayed
- To: mathgroup at smc.vnet.net
- Subject: [mg63782] Re: Question about UpSet vs SetDelayed
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Sat, 14 Jan 2006 02:32:26 -0500 (EST)
- References: <dq7u2s$3r6$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, the information is stored in different places. someFunc[a]:=a store the information at the symbol "someFunc" and someOtherFunc[b]= store the information at b. So if you remove b the information is removed too, to remove someFunc[a]:=a you must remove someFunc[] and not a. Regards Jens "Andy Somogyi" <andy_somogyi at hotmail.com> schrieb im Newsbeitrag news:dq7u2s$3r6$1 at smc.vnet.net... > Hello > > I'm trying to work out what how exactly := and ^= differ and what are uses > for ^=. > > Say I want to have some 'properties' of a symbol 's', I can do: > > someFunc[s] := True; > > and I can also do: > > someOtherFunc[s] ^= True; > > When I execute either, someFunc[s] and someOtherFunc[s], they both > obviously > return True, and when I apply them to some other symbol or value for which > they are not defined for, they both obviously return the expected result: > > In[20]:= someFunc[SomethingOtherThanS] > Out[20]:= someFunc[SomehingOtherThanS] > > and > > > In[20]:= someOtherFunc[SomethingOtherThanS] > Out[20]:= someOtherFunc[SomehingOtherThanS] > > So, both := and ^= aperently behave very similarly, so my question how > exactly do they differ and in what cases should I use one over the other? > > thanks > >