Re: List manipulation question
- To: mathgroup at smc.vnet.net
- Subject: [mg15898] Re: [mg15852] List manipulation question
- From: BobHanlon at aol.com
- Date: Wed, 17 Feb 1999 23:33:43 -0500
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 2/12/99 8:48:03 PM, Maarten.vanderBurgt at icos.be writes:
>In the following piece of code I define a function Swap23 which is ment
>to swap elements 2 and 3 in a list.
>Executing the function on a simple list I get an error. Why do I get
>this error? Why do I not get this error when I execute the commnad from
>Swap23 "by hand" as is shown in In[4]?
>
Maarten,
Use the following:
Swap23[L_List]:=Module
[
{a = L, temp},
temp = a[[2]];
a[[2]]=a[[3]];
a[[3]] =temp;
a
]/; Length[L] > 2
myList = {1,2, 3};
Swap23[myList]
{1,3,2}
Bob hanlon