Random selection without replacement.
RandomSample[{e1, e2, …}, n]
RandomSample[{w1, w2, …} -> {e1, e2, …}, n]
RandomSample[{e1, e2, …}]
Length[RandomSample[{a, b, c}]]
→ 3RandomSample[{1, 2}, 5]
→
RandomSample::smplen: RandomSample cannot generate a sample of length 5, which is greater than the length of the sample set {1, 2}. If you want a choice of possibly repeated elements from the set, use RandomChoice.
RandomSample[{1, 2}, 5]