字符串逆序(lua实现）

function reverse(s)
    local r = ""
    for i = #s, 1, -1 do
        r = r .. string.sub(s, i, i)
    end
    return r
end

io.write("Input a string: ")
s = io.read()
io.write("The reverse string is: ")
io.write(reverse(s) .. "\n")