Can I use logical indexing to find how many times a character is in a string?

Hi,

I was working on a problem in this MOOC course where I had to count the number of times a character was present in a text file.

While solving the problem, I used a while loop to read each line and just added the length of the array(after using strfind)

like so:

line = fgets(fid);

sum=0;

while ischar(line)

found_in_line = length(strfind(line,character));

sum = sum + found_in_line;

line=fgets(fid);

end

But I tried to just make a sum of a logical array using logical indexing

Like so:

found_in_line = sum(contains(line,character));

But what contains does is just return true if its found in the entire string, I even tried using contains(line(1:end),character)) but this also returns only one logical answer.

Is there a method that I am not aware of which can create a logical array of a character found in a String??

Thank you!

Answer 1

[Stephen23]

You can perform logical comparisons on a character array (they are not very different from numeric arrays):

str = 'some random text';
nnz(str=='o') % how many 'o' characters

ans = 2

Knowing how to work with arrays is a very powerful approach to using MATLAB.

[Mayank Mohan Arora]

ohhhh yesss lmaooo i totally forgot the single quotes xD

thank you!

[Stephen23]

Strings are a container array which have character arrays inside. Hence if you want to deal with individual characters, you need to process the character arrays.