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

Answer 1

I preferred James version for its simplicity and use it in my utils.lua - i did add a check for table type for error handling.

function merge(a, b)
    if type(a) == 'table' and type(b) == 'table' then
        for k,v in pairs(b) do if type(v)=='table' and type(a[k] or false)=='table' then merge(a[k],v) else a[k]=v end end
    end
    return a
end

Thanks for this nice function which should be part of the table class so you could call a:merge(b) but doing table.merge = function(a, b) ... did not work for me. Could even be compressed to a one liner for the real nerds :)