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Re: ReplacePart in an If[] construct?

• To: mathgroup at smc.vnet.net
• Subject: [mg67834] Re: [mg67816] ReplacePart in an If[] construct?
• From: gardyloo <gardyloo at mail.wsu.edu>
• Date: Sun, 9 Jul 2006 04:51:29 -0400 (EDT)
• References: <NDBBJGNHKLMPLILOIPPOKEBBFBAA.djmp@earthlink.net>
• Sender: owner-wri-mathgroup at wolfram.com

  To all who responded to my question below: Thank you. Especially to
(so far) David Park, Bob Hanlon, and
Andrzej Kozlowski.
>
> From: gardyloo [mailto:gardyloo at mail.wsu.edu]
To: mathgroup at smc.vnet.net
>
>
> Hi, all,
>
>    It's probably that I'm too tired, but I have a question about using
> ReplacePart in an If[] construct. I've made up a (very) minimal example:
>
> In[1]:=
> testList = {{3, an, example, list},
>    {4, another, example, list}}
>
> Out[1]=
> {{3, an, example, list}, {4, another, example, list}}
>
> In[2]:=
> (If[  (ListQ[#1] && First[#1] == 4),
>     ReplacePart[#1, replaced!, 3];
>     ReplacePart[#1, replaced!, 2],
>    #1      (*otherwise*)
> ] & ) /@ testList
>
> Out[2]=
> {{3, an, example, list}, {4, replaced!, example, list}}
>
>
>         Can someone tell me why BOTH the second and third positions in
> the second element in testList aren't turned to "replaced!" ?  I have
> plenty of other ways of doing this, but this seemed the most
> straightforward, and I can't wrap my head around it, for some reason.
>
>   

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Curtis Osterhoudt          
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