Assigning a symbolic expression with sprintf command

Hello guys, I'm trying to implement a code where I define a symbolic function and I want to find out its partial derivatives (first and second) also in a symbolic way. The example is below:

    prompt = ('\n Type the function: ');
    f = sym(input(prompt,'s'));
    prompt = ('\n Type the number of independent variables: ');
    n1 = (input(prompt));
    n2=n1;
    for i=1:1:n1
    syms(sprintf('x%d', i));
    syms(sprintf('df%d', i));
        for j=1:1:n2
        syms(sprintf('df%d%d', i,j));
        end
    end

For n=2, I get the following result (all symbolic variables): x1, x2, df1, df2, df11, df12, df21 and df22.

Now I want to assign to each of these variables the proper partial derivative, for example:

df1 = diff(f,x1)
df2 = diff(f,x2)
df11 = diff(df1,x1)
df12 = diff(df1,x2) and so on...

How can I put these diff commands in a loop??

[Karan Gill]

To confirm, another user is interactively entering the function? That is, you are not defining the function yourself, correct?