Re: Sorting strings
- To: mathgroup at smc.vnet.net
- Subject: [mg123142] Re: Sorting strings
- From: "Oleksandr Rasputinov" <oleksandr_rasputinov at hmamail.com>
- Date: Thu, 24 Nov 2011 06:58:22 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jainvm$eop$1@smc.vnet.net>
On Wed, 23 Nov 2011 12:12:38 -0000, Themis Matsoukas <tmatsoukas at me.com>
wrote:
> Sorting this list of strings
>
> {"a1", "a2", "a20", "a12"} // Sort
>
> I get
>
> {"a1", "a12", "a2", "a20"}
>
> but I would like the numerals to be sorted as numbers, i.e., as
>
> {"a1", "a2", "a12", "a20"}
>
> Is this possible or do I have to rename "a1" into "a01" etc?
>
> Thanks
>
> Themis
>
You could try:
lst = {"a1", "a12", "a2", "a20"};
nums =
ToExpression@StringTrim[{"a1", "a12", "a2", "a20"}, LetterCharacter]
{1, 12, 2, 20}
Part[lst, Ordering[nums]]
{"a1", "a2", "a12", "a20"}