Lua --- 檢查某個值第x位是否爲1

代碼如下：

function checkBit(value,nbit)
	local tmp1 = 2^(nbit + 1)
	local tmp2 = 2^nbit
	local ret = 0
	ret = value % tmp1
	ret = ret / tmp2
	if ret >= 1 then
		return 1
	else
		return 0
	end
end

print(checkBit(4098,1))   --輸出1
print(checkBit(4098,0))   --輸出0