MATLAB: What is wrong in the square wave code it isnt running

Question

clc;

clear vars;

close all;

a=[1,1,1,1,0,0,0,0];

fs=10;

tiv=1/fs;

t=0:tiv:(3-tiv);

plot(t,a,'*');

axis([0 3 -0.5 1.5]);

xlabel('sec.');

title('square wave samples');

Answer 1

You have 30 values of t and only 8 values of a. You need to have the same number of each.