After the variable is computed, you can list the variable's name by itself on it's own line in your function code, with no semicolon after it. When execution hits that line of code, it will spew the value of the variable out to the command window.
Example: The following code displays the values of b taken in function "test".
test(4)
function [] = test(jmax)
for j = 1:jmax
a = 2*j;
b = 3 + a;
b
end
end
