detecting the existence of alphabetical elements

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Dear all, I would like to detect whether a string contains an alphabetical letter. A simple way of solving this problem is writing a function such as. But is there any better, more concise and faster way? Can one use, say, regular expressions and if so how?
thanks, Pat.
function flag=detect_alphabet(mystring)
referenceSet={'a','b','c','d',...,'z'};
flag=false;
for ii=1:length(mystring)
if ismember(mystring(ii),referenceSet)
flag=true;
break
end
end

Accepted Answer

Matt Fig
Matt Fig on 1 Oct 2012
Edited: Matt Fig on 1 Oct 2012
Perhaps best of all:
str = 'adsf2342adsfwerreoj9f3f';
str2 = '23423';
flag = any(isletter(str))
flag = any(isletter(str2))

More Answers (4)

Oleg Komarov
Oleg Komarov on 1 Oct 2012
regexpr(str,'[a-zA-Z]')

Matt Fig
Matt Fig on 1 Oct 2012
Edited: Matt Fig on 1 Oct 2012
str = 'adsf2342adsfwerreoj9f3f';
str2 = '23423';
flag = ~isempty(regexp(str,'[A-Za-z]'))
flag = ~isempty(regexp(str2,'[A-Za-z]'))

Jan
Jan on 1 Oct 2012
Edited: Jan on 1 Oct 2012
flag = any(ismember(mystring, 'a':'z'))
But now I'm lost in the incompatibilities of Matlab versions. Perhaps it must now be:
flag = any(ismember(mystring, char('a':'z')))
Alternatively:
flag = any(mystring >= 'a' & mystring <= 'z')
Or:
flag = any(isstrprop(mystring, 'lower'))
In all cases a loop is not required.

Patrick Mboma
Patrick Mboma on 1 Oct 2012
Dear all, thank you SO much for a prompt reply. I now have many suggestions but don't know which one is the best. I will test them all and see, which one works best.
  1 Comment
Image Analyst
Image Analyst on 1 Oct 2012
Well for what it's worth, I was going to answer isletter() until Matt beat me to it.

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