# How to reset a variable in a for loop?

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Andrea Miceli on 21 Sep 2021
Commented: Rik on 22 Sep 2021
Hello evreyone,
I was wondering if there is a way to reset variables in a for loop, I am going to show you an example to be as clear as possible,
for i=1:10
X=1+rand()
Y=["A","B","C"];
end
What I want to achieve is to clean up the X variable, that is, every time the for loop starts over, the X variable is cleared and recreated. I know it is very expensive for the pc, but all the values obtained in one click are stored in another variable and I need to recreate X. (I know well that in the example I have proposed the values are overwritten, but in the code that I am writing at each loop the values in the variable increase and are not overwritten)
Andrea Miceli on 22 Sep 2021
I think you're right, I will try to make a function and use a for loop on the function. Thank you Stephen, It wasn't easy for me explaining what I want to do, but I think this is the best way to get what I want!
Rik on 22 Sep 2021
Then it seems something like I suggested in your duplicate question should do what you want. Simply create your variables once and then pass them as parameters to your function. Using a struct can help to limit the number of input parameters so you don't get confused by the order (and so you can easily add new ones).

Adam Danz on 21 Sep 2021
Edited: Adam Danz on 21 Sep 2021
The example isn't very clear but I think you want to preserve the random X values within the loop. If so,
n = 10; % number of iterations
x = nan(1,n);
for i = 1:n
x(i) = 1+rand();
...
end
Of course in this example, you could generate all x values at once using x = 1+rand(1,n);

David Hill on 21 Sep 2021
Use indexing.
X=1+rand(1,10);
for i=1:10
Y=X(i)+5;%whatever you do.
end