How can I find the number of letters in a string? Just letters (A-Z, a-z)?

How can I find the number of letters in a string? Just letters (A-Z, a-z)?

Answer 1

[Star Strider]

Easiest way:

string = 'This is a string.';
NrLtrs = length(regexpi(string, '[a-zA-Z]'));

The number of letters only is returned in the ‘NrLtrs’ variable.

[yashar khatib shahidi]

I have a question about text files. how to calculate the total number of letters (A-Z, a-z) in the whole text file?

[Star Strider]

I would believe the same way. The text file would have to be in the same variable, so you would have to read the entire file in first.

[yashar khatib shahidi]

I did like this but it gives error:

fid = fopen(filename, 'rt');
if fid < 0
    -1;
    return;
end
s = textscan(fid,'%s','Delimiter','\n');
num = length(regexpi(s, '[a-zA-Z]'));
fclose(fid);
disp(num);

[Star Strider]

What error does it give?

What line?

[yashar khatib shahidi]

Error using regexpi
All cells must be strings.

Error in letter_counter (line 8)
num = length(regexpi(s, '[a-zA-Z]'));

[Image Analyst]

Why are you using textscan to simply get a string. That's too overkill for a simple case like this. Simply use fgetl() if you want to get line by line, or use fread() if you want to suck up the whole file in one shot.

[Star Strider]

If it’s a cell, address it as a cell:

string = {'This is a string.'};
NrLtrs = length(regexpi(string{1}, '[a-zA-Z]'));

You will likely have to experiment with this idea in the context of your code to get the result you want.

Answer 2

[yashar khatib shahidi]

Thanks.

[Star Strider]

My pleasure!

Answer 3

[Jan]

Or:

sum(isstrprop(string, 'alpha'))