character to variable that already exists in the workspace

I want to make a "for loop" that uses some variables that looks like this: score1, score2, score3,...score21. My problem is that I cannot connect both string 'score' and the number (represented by 'i') as a whole string. the script is:

for i=1:21
    [r c]=size(strcat('score', num2str(i)));
    for j=2:r
        strcat('cscore', num2str(i))(j-1)=strcat('score', num2str(i))(j)+strcat('score', num2str(i))(j-1);
    end
end

after this, the value of this variable is a 'char' rather that a string.

thank you, Ziv.

[Stephen23]

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Answer 1

[Geoff Hayes]

Ziv - use sprintf to "concatenate" the number to the string. Try

 for k=1:21
     str = sprintf('score%d',k);
 end

str will be one of score1, score2, etc. This code will create the variable name and then you will have to evaluate it using (most likely) eval.

But ask yourself is this really necessary? Can't you put all of these scores into a matrix or cell array and so avoid these individual variables? While MATLAB allows you to do the above and evaluate strings etc. it is not usually a good habit to get in to.

[Ziv Kassner]

Thank you very much. the problem is that I have many vectors with different lengths, so I can't put them together in the same matrix.

[Geoff Hayes]

Ziv - since the vectors are of different lengths, you can use a cell array to store each one.

Answer 2

[Jos (10584)]

You should store your data into structs or in cell arrays:

scoreStruct(1).values = [1 2 3]
scoreStruct(2).values = 10
scoreStruct(3).values = 10:20

scoreCell = {[1 2 3], 10, 10:20}

Learn about structs and cell arrays now an save yourself a lot a of trouble in the future!

Never ever use eval for this !! (Can I make this red?)

[Stephen23]

Sadly this advice was ignored:

https://www.mathworks.com/matlabcentral/answers/406131-how-can-i-change-struct-name-in-a-loop