How can I find a character in a string?

I am searching a textfile line by line for a particular character. Each line is being saved into a string format and then gets searched for the character. Written below is a section of the function I am using. None of the inbuilt string compare functions seem to be able to do this one task: find a character in a string and release the logical '1' if the character is there.

Am I missing a function? If not, how then do I do this please?

    
oneline = fgets(fid);
  while ischar(oneline)
      strncmp(character,oneline,strlength(oneline));
      oneline = fgets(fid);
      
  end      
      

[Stephen23]

"Am I missing a function?"

The simplest one of all:

s = 'hello world';
x = s=='l'

x = 1×11 logical array
   0   0   1   1   0   0   0   0   0   1   0

[Karis Anoruo]

Thank you!

Answer 1

[Yongjian Feng]

ismember is the function you are looking for.

[Karis Anoruo]

Thank you!

Answer 2

[Sulaymon Eshkabilov]

Hi,

Here is one of the many possible solutions to your exercise:

clearvars
fid = fopen('TEXT__R.txt', 'r');   % Your text file
Letter = 'a';                      % Looking for letter "a" 
ii=1;
while 1
    tline = fgetl(fid);
    if ischar(tline)
        fprintf('Searched line: %d \n', ii)
        IDX =strfind(tline, Letter)                     % Index of "a" character location 
        N = numel(IDX);
          fprintf('%5d "a" character was found \n', N)  % Display the found results
        ii=ii+1;
     end
 end
 fclose(fid);