generate 0 and 1

how do I generate a binary sequence with certain probabilities? 

for instance, I want 0 to have 0.6 and 1 to have 0.4 probability

It would be very helpful if you give me the whole code to this

Answer 1

[John D'Errico]

rand() < 0.6

If you want a random binary sequence of length n, then this is sufficient:

rand(1,n) < 0.6