You want this: object:addShape(unpack(values)) See also: http://www.lua.org/pil/5.1.html Here’s a complete example: shape = { addShape = function(self, a, b, c) print(a) print(b) print(c) end } values = {1, 2, 3} shape:addShape(unpack(values))
Which to use is a matter of preference and circumstance: as the # length operator was introduced in version 5.1, t[#t+1] = i will not work in Lua 5.0, whereas table.insert has been present since 5.0 and will work in both. On the other hand, t[#t+1] = i uses exclusively language-level operators, wheras table.insert involves … Read more
A table in Lua is a set of key-value mappings with unique keys. The pairs are stored in arbitrary order and therefore the table is not sorted in any way. What you can do is iterate over the table in some order. The basic pairs gives you no guarantee of the order in which the … Read more
Lua doesn’t have strict arrays like other languages – it only has hash tables. Tables in Lua are considered array-like when their indices are numerical and densely packed, leaving no gaps. The indices in the following table would be 1, 2, 3, 4. local t = {‘a’, ‘b’, ‘c’, ‘d’} When you have an array-like … Read more
The correct way to write this is either local t = { foo = 1, bar = 2} Or, if the keys in your table are not legal identifiers: local t = { [“one key”] = 1, [“another key”] = 2}
local keyset={} local n=0 for k,v in pairs(tab) do n=n+1 keyset[n]=k end Note that you cannot guarantee any order in keyset. If you want the keys in sorted order, then sort keyset with table.sort(keyset).
Overcomplicated answers much? Here is my implementation: function TableConcat(t1,t2) for i=1,#t2 do t1[#t1+1] = t2[i] end return t1 end
Table copy has many potential definitions. It depends on whether you want simple or deep copy, whether you want to copy, share or ignore metatables, etc. There is no single implementation that could satisfy everybody. One approach is to simply create a new table and duplicate all key/value pairs: function table.shallow_copy(t) local t2 = {} … Read more
You could use something like a set from Programming in Lua: function Set (list) local set = {} for _, l in ipairs(list) do set[l] = true end return set end Then you could put your list in the Set and test for membership: local items = Set { “apple”, “orange”, “pear”, “banana” } if … Read more
To iterate over all the key-value pairs in a table you can use pairs: for k, v in pairs(arr) do print(k, v[1], v[2], v[3]) end outputs: pears 2 p green apples 0 a red oranges 1 o orange Edit: Note that Lua doesn’t guarantee any iteration order for the associative part of the table. If … Read more