编辑代码

local function foo(n)
        if n == 0 then return 1
    else
        return n*foo(n-1)  
    end
end
print(foo(4))


local foo; foo = function(n)
        if n == 0 then return 1
    else
        return n*foo(n-1)  
    end
end
print(foo(4))