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Re: Sorting strings

  • To: mathgroup at
  • Subject: [mg123129] Re: Sorting strings
  • From: Bill Rowe <readnews at>
  • Date: Thu, 24 Nov 2011 06:56:00 -0500 (EST)
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On 11/23/11 at 7:07 AM, tmatsoukas at (Themis Matsoukas) 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?

Here is one way

In[1]:= list = {"a1", "a2", "a20", "a12"};

In[2]:= list[[Ordering[ToExpression[StringReplace[list, "a" -> ""]]]]]

Out[2]= {a1,a2,a12,a20}

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