Find Number of values filtered through conditioned for loops

I have a for-loop in which I'm generating x & y values and filtering them under conditions to prepare them for another, nested for-loop. I want to know how to get the amount of values left after filtering so I can run the next for-loop for that many iterations. As below, I start with 100 random values and have them filtered by an if statement, so how can I get the count of the filtered values? If I try to fill in a matrix it only fills in values from the last iteration.

filtered_array=[];

for i=1:100
x = rand;
y = rand;
    if (abs(x)<=1/2) && (abs(y)<=1/2)    % Filtering
             filtered_array = [x y]     % Maybe populate a matrix?
                for i=1:length(filtered_array)  % for loop only iterating as few times as it needs
                    ...
                end
    end
end

Answer 1

[David Hill]

No loops needed.

x=rand(1,100);
y=rand(1,100);
filtered_array=[x(abs(x)<=.5),y(abs(y)<=.5)];
a=length(filtered_array);%this provides the length