Lua使用元方法操作两个table元素进行加减乘

Lua使用元方法操作两个table元素进行加减乘

local mt = {}
mt.__add = function(mytable, othertable)
    local temp = {}
    for i,v in ipairs(mytable) do
        temp[i] = v + othertable[i]
    end
    return temp
end
mt.__sub = function(mytable, othertable)
    local temp = {}
    for i,v in ipairs(mytable) do
        temp[i] = mytable[i] - othertable[i]
    end
    return temp
end
mt.__mul = function(mytable, othertable)
    local temp = {}
    for i,v in ipairs(mytable) do
        temp[i] = mytable[i] * othertable[i]
    end
    return temp
end
 
function show(mytable)
    for i,v in pairs(mytable) do
        print("table["..i.."] = "..v)
    end
    print('--分割线--')
end
 
function main()
    local mytable = {1,2,3}
    setmetatable(mytable, mt)
    local secondtable = {20,30,50}
 
    local newtable = mytable + secondtable
    show(newtable)
 
    local newtable = mytable - secondtable
    show(newtable)
 
    local newtable = mytable * secondtable
    show(newtable)
 
end
 
main()