Lua - merge tables?

Question

I need to merge two tables, with the contents of the second overwriting contents in the first if a given item is in both. I looked but the standard libraries don't seem to offer this. Where can i get such a function?

Answer 1

for k,v in pairs(second_table) do first_table[k] = v end

Answer 2

Here's what i came up with based on Doug Currie's answer:

function tableMerge(t1, t2)
    for k,v in pairs(t2) do
     if type(v) == "table" then
      if type(t1[k] or false) == "table" then
       tableMerge(t1[k] or {}, t2[k] or {})
      else
       t1[k] = v
      end
     else
      t1[k] = v
     end
    end
    return t1
end