table.unpack

Sometimes you have values in an array but need them as separate values: say, to pass each element as its own argument. That's table.unpack: it returns all the elements of an array, spread out.

local scores: {number} = {85, 92, 78}
print(table.unpack(scores))           -- 85  92  78 (one line)
print(math.max(table.unpack(scores))) -- 92

print receives three arguments, so it prints them on one line with a tab between them. math.max wants separate numbers, not an array, so unpacking is what makes the call work.

table.unpack reads the array without changing it. The other direction, a function that takes any number of arguments with ..., comes in the Variadic Functions lesson of the next chapter.