I agree with cvklpstunc that you dont need a while loop. If you are still looking for a while loop implementation, here is the code
count=1;z=1;
a=[1:10, zeros(5,1)'];
while count<=length(a)
if a(count)==0
zero_indices(z)=count;
z=z+1;
end
count=count+1;
end
a(zero_indices)=[];
Here is one line answer for what you want to do
b=a(find(a))
