select random number from a variable

how to select 4 values from already assigned variables

a= [4 5 1 2 9 7 8 1]

select 4 values from a in random fashion

Answer 1

[Andrei Bobrov]

out = a(randperm(numel(a),4));

or

ii = randperm(numel(a));
out = a(ii(1:4));