setcookie("cookie_one","A",time()+60*60); //cookie在一小时后失效 setcookie("cookie_two","B",time()+60*60*24); //cookie在一天后失效 setcookie("cookie_three","C",mktime(23,53,19,10,09,2020)); //cookie在2020年10月9日23时53分19秒失效 setcookie("cookie_four","D"); //关闭浏览器后cookie失效