Tables are very convenient and allow us to implement data structures such as dictionaries, sets, lists, and arrays very efficiently. A table can be initialized empty or with some values:

T1={} --empty table
T2={"a","b","c"}

Integer indexes or hash keys can be used to assign or dereference the values in a table. One important thing to keep in mind is that we can have both types in the same table:

t={}
t[1] = "hey "
t["nmap"] = "hi " --This is valid

To get the number of elements stored in a table, you may prepend the # operator:

if #users>1 then
print(string.format("There are %d user(s) online.", #users))
  … --Do something else
end