how do I make first name of my struct variable?

Hello all, I'm trying to make the first name of my struct variable but I can't figure out how to do it.

This works

test.a = 1;
List = 'a';
test.(List)

ans =  1

I'm trying to do the following:

test.a = 1;
List = 'test' 
(List).a

%now I want to get the output test.a but I get:

(List).a
      |
Error: Unexpected MATLAB operator.

Is it possible what im trying to do and if so how?

regards, Nick

[Friedrich]

Why do you need this? This doesn't seem like a good way of programming. Maybe if you explain why you need this, we can help you with a better more suitable way of achieving your goal?

[Nick]

I have several counters that have different numbers I need to test. I can put them in a string easy using somthing like this:

CounterNumber = 2;
List = sprintf('%s%d','Counter',CounterNumber)
%output List:  Counter2

this i want to use to test what value's my counters have in an for loop:

for ii = 1:Amount
   if List.value(ii) == 1
      count = count+1;
      if count == Amount
         CountingDone = true;
      else
         CountingDone =false;
      end
   else 
      CountingDone = false;
   end
end

If I have to make an forloop for every counter I have I would go over 60 loops.

Answer 1

[David Sanchez]

List = 'test' ;
eval(strcat(List,' .a = 1'));

test = 

      a: 1

[Nick]

works perfect thankyou

[Jan]

No. Nick, this is not perfect, but a bad programming method. You find hundreds of warnings about the EVAL command in this forum. It impedes the debugging and slows down Matlab noticeably, because it injects variables dynamically. There are always better solutions.

[Nick]

Thanks for the advice on programming Jan Simon. I changed my structs from several to one struct like this:

before:

counter1.data
counter2.data
...
counterX.data

after:

for jj = 1:X
  for ii = 1:n
    counter(jj).data(ii)
  end
end

With this I don't need the EVAL command anymore.

Regards,

[Jan]

This is a nice and efficient solution! Thanks for posting it, Nick.