MATLAB not breaking when r=1

%% test

clear
clc
clf

moves = {};
% Create a 2D array of size 8x8 containing zeros
a = zeros(8, 8);

% Set the pixel at position (3,3) to 1
a(3, 3) = 1;

% Determine the size of the matrix a
[y_len, x_len] = size(a);

% Nested for loop to iterate through all y and x coordinates
for y = 1:y_len
    for x = 1:x_len
        % Check if the value at a(y,x) is equal to 1 (gas particle exists)
        if a(y, x) == 1
            % Choose a random number between 0 and 3
           %r = floor(rand*3.9999); % rand gives value between 0 and 1 so multiplying by close to 3.9999 will give values from 0 to 3.9999 which when using float will round to 0 to 3
          r = 1;
           moves = [moves,r];
            % Move the gas particle based on the random number
            if r == 0
                % Move up
                a(y-1, x) = 1;
                a(y, x) = 0;
                disp('Moving particle up')
                break
            elseif r == 1
                % Move down
                a(y+1, x) = 1;
                a(y, x) = 0;
                disp('Moving particle down')
                break
            elseif r == 2
                % Move left
                a(y, x-1) = 1;
                a(y, x) = 0;
                disp('Moving particle left')
                break
            elseif r == 3
                % Move right
                a(y, x+1) = 1;
                a(y, x) = 0;
                disp('Moving particle right')
                break
            end
        end
    end
end