【JavaScript代码实现四】获取和设置 cookie

 // 创建cookie
 function setCookie(name, value, expires, path, domain, secure) {
     var cookieText = encodeURIComponent(name) + '=' +encodeURIComponent(value);
     if (expires instanceof Date) {
         cookieText += '; expires=' + expires;
     }
     if (path) {
         cookieText += '; expires=' + expires;
     }
     if (domain) {
         cookieText += '; domain=' + domain;
     }
     if (secure) {
         cookieText += '; secure';
     }
     document.cookie = cookieText;
 }
 // 获取cookie
 function getCookie(name) {
     var cookieName = encodeURIComponent(name) + '=';
     var cookieStart = document.cookie.indexOf(cookieName);
     var cookieValue = null;
     if (cookieStart > -1) {
         var cookieEnd = document.cookie.indexOf(';', cookieStart);
         if (cookieEnd == -1) {
             cookieEnd = document.cookie.length;
         }
         cookieValue = decodeURIComponent(document.cookie.substring(cookieStart + cookieName.length, cookieEnd));
     }
     return cookieValue;
 }
 // 删除cookie
 function unsetCookie(name) {
     document.cookie = name + "= ; expires=" + new Date(0);
 }