print(table.getn{10,2,4}) --> 3
print(table.getn{10,2,nil}) --> 2
print(table.getn{10,2,nil; n=3}) --> 3
print(table.getn{n=1000}) --> 1000
a = {}
print(table.getn(a)) --> 0
table.setn(a, 10000)
print(table.getn(a)) --> 10000
a = {n=10}
print(table.getn(a)) --> 10
table.setn(a, 10000)
print(table.getn(a)) --> 10000