How to read multiple files from matlab workspace?

I have multiple files (sub1, sub2, sub3......subn) in matlab workspace and wants to apply a loop to extract the features. There is error in the code. Kindly guide me to fix this issue. My code is as follow:

s=43;
theta=[ ];
% numsubjects = length(sub);
 for sub_i=1:s
    subject = sub(str(sub_i));
    theta1=mean(subject(3:7,26,:));
    theta=[theta,theta1];
 end

[KSSV]

files or variables?

[Khan Muhammad Adeel Khan]

Thanks for the reply! It's variables from the workspace

Answer 1

[Walter Roberson]

Don't do that. Do not allow them to be created into different variables in the first place, and then you will not have to hack to dynamically create variable names.

[Khan Muhammad Adeel Khan]

Thanks for the feedback. I already have all these files (sub1,sub2....sub43) in matlab workspace. Now I want to extract features from these files. I need to apply loop to extract all the features.

[Rik]

Then you need to change how you get them in your workspace. You're forcing yourself to write terrible code. Why would you do that for no good reason?