Persistent variables not working? (Simulink)

I'm trying to implement the following simple test function in Simulink:

function [y, newx] = fcn(xI, T)
%This is a very simple function meant for learning how to properly
%implement "pseudo-feedback" in Simulink.
%xI is merely the initial value of x.
%#codegen
mlock

persistent currentX;
double x; 
if isempty(currentX)
    x = xI;
else
    x = currentX;
end

for t = 1:T
    if t > 1
        newx = x;
    end
    y = 1/x;
    newx = x+1;
end

end

However, when I try running the model (with a constant input and displays connected to the output), I get the following error message:

Undefined function or variable 'currentX'. The first assignment to a local variable determines its class.

Could anyone help identify the problem?

[Jared Mach]

Remove the semicolon at the end of "persistent currentX;"

Answer 1

[Azzi Abdelmalek]

currentX is not defined in your code