Re: How to Return from within a Table[]-Command?
- To: mathgroup at smc.vnet.net
- Subject: [mg33753] Re: How to Return from within a Table[]-Command?
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Thu, 11 Apr 2002 02:14:07 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <a90goo$kdb$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
a) use a pattern to restrict the argument
Divide2[L:{__Integer}]:=
b) Catch[] and Throw[] are for nonlocal returns
Divide2[L_List] := Catch[
Table[
If[IntegerQ[L[[i]]], i/2, Throw[$Failed]], {i, 1, Length[L]}]
]
Regards
Jens
Detlef Mueller wrote:
>
> Hello,
>
> I wanted to scan trough al List, building a new
> List, but aborting, if one Element of the first
> List violates a special Condition ...
> say for example:
>
> Divide2[L_List] := Module[{},
> Table[
> If[IntegerQ[L[[i]]],
> i/2,
> Return["vector not valid."];
> ]
> , {i, 1, Length[L]}
> ]
>
> ...
>
> ]
>
> But this results:
>
> In[13]:= Divide2[{2,3,a}]
> Out[13]= {1/2, 1, Return["vector not valid."]}
>
> Wich is of course not what I want.
>
> Greetings
>
> Detlef