Find the longest word in a character vector

I have to write a function that consumes a character vector in the form of a sentence and returns the longest word to in the string to the user.

I think I am on the right track but I'm stuck.

This is what I have so far.

function word = longest_word(phrase)

      code = double(phrase);

      i_spaces = find(code == 32);

      word = char(code(1:i_spaces(1)));

      for i = 1:length(i_spaces)

          if (i+1) > length(i_spaces)

              break

          elseif length(code(i_spaces(i)+ 1:i_spaces(i)))>length(word)

              word = char(code(i_spaces(i)+ 1:i_spaces(i)));

          end
      end

end

i_spaces is the vector containing the locations of every space in between words.

Answer 1

[Andrei Bobrov]

phstr = 'etetetettete fhfhfh fg fgfgf tdfhfjfkfkfk nfjfiekehdfjgjgugtltrj'
wcl = regexp(phstr,'\w*','match')
[~,ii] = max(cellfun('length',wcl))
out = wcl(ii)

Answer 2

[Walter Roberson]

Words do not end only with spaces; they can end with any punctuation mark. Beware the apostrophe, which might mark the end of something being quoted, or might mark the possessive form, or might mark a contraction. Beware that commas and periods do not mark the end of a "word" when the word is a number. Beware that currency signs might come before or after a number, and if immediately adjacent to the number are sometimes considered to be part of that "word".

If you know the locations of all of words and have created a canonical form of changing all non-word characters to spaces and then all runs of spaces to single spaces, then think about using diff()

[Danny]

This question is for an introductory MATLAB course and we are only considering spaces as word separators for simplicity.

And I am only allowed to use commands I have learned in class. Unfortunately diff is not one of them.

Thank you for your answer.

[Walter Roberson]

diff(x) for a vector x, is x(2:end) - x(1:end-1), and you've learned those commands.

Answer 3

[Humberto Lopez Franco]

Does anyone care to optimize it for me???

clear;clc
fprintf(2,'I can tell you the longest word in your sentence!\n');
x=input('Go ahead, say something: ','s');
TF=isletter(x);
limit=size(x);
i=1;

while i<=limit(2)
    if TF(i)~=1
       x(i)=' ';
      i=i+1;
    else
    i=i+1;
    end
end

answer=strsplit(x);

i=1;
limit=size(answer);
y=zeros(1,limit(2));

while i<=limit(2)
    y(i)=strlength(answer(i));
    i=i+1;        
end

i=1;
j=2;

while i<=limit(2) && j<=limit(2)
    if y(i)>=y(j)
        j=j+1;
    else
        i=j;
        j=j+1;
    end
end
A=string(answer(i));
fprintf('\n\nOk, so "%s" is the longest word in your sentence with a mere %i letter(s).\n\n',A,y(i))

[Walter Roberson]

No need to loop near the beginning.

x(~isletter(x)) = ' ';

[Walter Roberson]

arrayfun(@strlength, ...)