# for loop that changes specific letters to numbers

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Seaturtle on 2 Oct 2019
Commented: Adam Danz on 4 Oct 2019
I want to replace the vowels AEIOU with the number 0 and all other letters with the number 1. For example the output should be ans = [0 1 1 1 0] if the user inputs apple. I know I must be misunderstanding how to get the loop to go through my whole string. This is what I have managed so far.
n = length(party)
for i = 1:n
if i == 'A'
disp(0)
elseif i == 'B'
disp(1)
elseif i == 'C'
disp(1)
end
end

Walter Roberson on 2 Oct 2019
n = length(party)
for i = 1:n
if party(i) == 'A'
party(i) = 0;
elseif i == 'B'
party(i) = 1;
elseif i == 'C'
party(i) = 1;
end
end
disp( double(party) )

Seaturtle on 3 Oct 2019
I ended up making the changes myself with the original answer that you posted, so it worked out great. Thank you!
Guillaume on 3 Oct 2019
It would be nice if 'vowel' were a category option.
The problem with that is what is a vowel or not depends on the language. Some letters such as 'y' in english can also qualify as a vowel or consonant depending on the word.
Adam Danz on 3 Oct 2019
True. It would be neat to play around with one of the vowel classification algorithms that are not specific to any language such as this one (link below) that is based on character co-occurrences. It wouldn't necessarily solve the fuzzy set problem but it would be a semi-objective, language-independent classification.

Adam Danz on 2 Oct 2019
Edited: Adam Danz on 2 Oct 2019
No loop needed.
str = 'apple';
isConsonant = ~ismember(lower(str),'aeiou') %lower() makes it not case sensitive
If you really wanted to do that in a loop,
n = numel(party);
isConsonant = true(1,n);
for i = 1:n
if ismember(party(i),'aeiou')
isConsonant(i) = false;
end
end
In both cases, isConsonant is a logical vector. If you want a double vector of 0/1 instead of false/true,
isConsonant = double(isConsonant);

Walter Roberson on 3 Oct 2019
semi-vowel does sound like the correct term.
In practice, y probably acts like a vowel more than it acts like a consontant .
Seaturtle on 3 Oct 2019
Thanks for this answer! This really helped with my understanding of not using a loop to do something with shorter code.
Adam Danz on 3 Oct 2019
Glad I could chip in! :)

Jos (10584) on 3 Oct 2019
Another option:
str = 'apple';
TF1 = any(lower(str) ~= 'aeiou'.')