Re: Select list elements and exchange them
- To: mathgroup at smc.vnet.net
- Subject: [mg109814] Re: Select list elements and exchange them
- From: Raffy <adraffy at gmail.com>
- Date: Wed, 19 May 2010 07:01:26 -0400 (EDT)
- References: <hstp64$mbi$1@smc.vnet.net>
On May 18, 3:12 am, ishii.mitsuo.titan... at nsc.co.jp wrote:
> Hi
>
> I have a problem.
>
> I have a list.
>
> testList={ {11,{2,3}},{21,{3,4}},{34,{5,6}},{51,{7,8}} }
>
> 1) From this list, select any element list such as {x,{3,4}},
>
> where X is an arbitrary number.
>
> In general, position of {x,{3,4}} in "testList" is not fixed.
>
> 2) Select any element list such as {x,{3,4}} and then exchange {x,{3,4}} to {100,{3,4}}.
>
> 3)Make a new list finally.
>
> testListNew={ {11,{2,3}},{100,{3,4}},{34,{5,6}},{51,{7,8}} }
>
> Please teach me how to solve.
>
> Thanks in advance.
>
> Mitsuo Ishii
ClearAll[sub];
sub[expr_, find_, replace_] := Replace[expr, {_, find} -> {replace,
find}, {1}];
sub[{{11, {2, 3}}, {21, {3, 4}}, {34, {5, 6}}, {51, {7, 8}}}, {3, 4},
100]
==> {{11, {2, 3}}, {100, {3, 4}}, {34, {5, 6}}, {51, {7, 8}}}