Help with picking out the first and last word in a string?

Hi,

My code so far is:

    Str=input('Give a string: ');
    ind=find(Str==' ');
    num_words=size(ind,2)+1;
    disp('Number of blank spaces:')
    disp(length(ind))
    disp('Number of words in the string:')
    disp(num_words)

I wanted to know how to display the first and last word from the string entered, any suggestions are appreciated :)

Answer 1

[Guillaume]

I would use numel(ind) instead of size(ind, 2), since ind is a vector.

As for your question, the first word is the content of Str up to the first space ( ind(1)-1) and the last is the content of Str from the last space( ind(end)+1), so:

 firstword = Str(1:ind(1)-1);
 lastword = Str(ind(end)+1:end);

[Guillaume]

Sounds like you're setting the field of a structure on a variable that was originally a double. This has nothing to do with the code I posted. The warning should have shown you the offending line (which would have been good to post).

The following would cause the warning:

somevar = 5; %somevar is double
somevar.somefield = 4; %somevar is now a struct

Answer 2

[Image Analyst]

I just use John D'Errico's allwords(): http://www.mathworks.com/matlabcentral/fileexchange/27184-allwords It splits apart a string into all the different words. It's very easy to use. (It has several options for tricky strings too.)

theWords = allwords('I wanted to know how to display the first and last word')
firstWord = theWords{1} % Extract the first word into its own variable.
lastWord = theWords{end} % Extract the last word into its own variable.

In the command window you'll see:

theWords = 
    'I'    'wanted'    'to'    'know'    'how'    'to'    'display'    'the'    'first'    'and'    'last'    'word'
firstWord =
I
lastWord =
word

[Guillaume]

Another option is to use strsplit

words = strsplit(sentence); %break each word at whitespaces

or a regular expression:

words = regexp(sentence, '\S*', 'match')