JavaScript 设置与读取 Cookie 的方法及本地测试注意事项

<script>
//设置cookie
function setCookie(cname, cvalue, exdays) {
 var d = new Date();
 d.setTime(d.getTime() + (exdays*24*60*60*1000));
 var expires = "expires="+d.toUTCString();
 document.cookie = cname + "=" + cvalue + "; " + expires;
}
//获取cookie
function getCookie(cname) {
 var name = cname + "=";
 var ca = document.cookie.split(';');
 for(var i=0; i<ca.length; i++) {
  var c = ca[i];
  while (c.charAt(0)==' ') c = c.substring(1);
  if (c.indexOf(name) != -1) return c.substring(name.length, c.length);
 }
 return "";
}
//清除cookie 
function clearCookie(name) { 
 setCookie(name, "", -1); 
} 
function checkCookie() {
 var user = getCookie("username");
 if (user != "") {
  alert("Welcome again " + user);
 } else {
  user = prompt("Please enter your name:", "");
  if (user != "" && user != null) {
   setCookie("username", user, 365);
  }
 }
}
checkCookie(); 
</script>

<script>
//JS操作cookies方法!

//写cookies
function setCookie(c_name, value, expiredays){
 　　　　var exdate=new Date();
　　　　exdate.setDate(exdate.getDate() + expiredays);
　　　　document.cookie=c_name+ "=" + escape(value) + ((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
 　　}
 
//读取cookies
function getCookie(name)
{
 var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
 
 if(arr=document.cookie.match(reg))
 
  return (arr[2]);
 else
  return null;
}

//删除cookies
function delCookie(name)
{
 var exp = new Date();
 exp.setTime(exp.getTime() - 1);
 var cval=getCookie(name);
 if(cval!=null)
  document.cookie= name + "="+cval+";expires="+exp.toGMTString();
}
//使用示例
setCookie('username','Darren',30) 
alert(getCookie("username"));
</script>

<html> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <head> 
  <script language="JavaScript" type="text/javascript"> 
   
   function addCookie(objName, objValue, objHours){//添加cookie 
    var str = objName + "=" + escape(objValue); 
    if (objHours > 0) {//为0时不设定过期时间，浏览器关闭时cookie自动消失 
     var date = new Date(); 
     var ms = objHours * 3600 * 1000; 
     date.setTime(date.getTime() + ms); 
     str += "; expires=" + date.toGMTString(); 
    } 
    document.cookie = str; 
    alert("添加cookie成功"); 
   } 
   
   function getCookie(objName){//获取指定名称的cookie的值 
    var arrStr = document.cookie.split("; "); 
    for (var i = 0; i < arrStr.length; i++) { 
     var temp = arrStr[i].split("="); 
     if (temp[0] == objName) 
      return unescape(temp[1]); 
    } 
   } 
   
   function delCookie(name){//为了删除指定名称的cookie，可以将其过期时间设定为一个过去的时间 
    var date = new Date(); 
    date.setTime(date.getTime() - 10000); 
    document.cookie = name + "=a; expires=" + date.toGMTString(); 
   } 
   
   function allCookie(){//读取所有保存的cookie字符串 
    var str = document.cookie; 
    if (str == "") { 
     str = "没有保存任何cookie"; 
    } 
    alert(str); 
   } 
   
   function $(m, n){ 
    return document.forms[m].elements[n].value; 
   } 
   
   function add_(){ 
    var cookie_name = $("myform", "cookie_name"); 
    var cookie_value = $("myform", "cookie_value"); 
    var cookie_expireHours = $("myform", "cookie_expiresHours"); 
    addCookie(cookie_name, cookie_value, cookie_expireHours); 
   } 
   
   function get_(){ 
    var cookie_name = $("myform", "cookie_name"); 
    var cookie_value = getCookie(cookie_name); 
    alert(cookie_value); 
   } 
   
   function del_(){ 
    var cookie_name = $("myform", "cookie_name"); 
    delCookie(cookie_name); 
    alert("删除成功"); 
   } 
  </script> 
 </head> 
 <body> 
  <form name="myform"> 
   <div> 
    <label for="cookie_name"> 
     名称 
    </label> 
    <input type="text" name="cookie_name" /> 
   </div> 
   <div> 
    <label for="cookie_value"> 
    值 
    </lable> 
    <input type="text" name="cookie_value" /> 
   </div> 
   <div> 
    <label for="cookie_expireHours"> 
    多少个小时过期 
    </lable> 
    <input type="text" name="cookie_expiresHours" /> 
   </div> 
   <div> 
    <input type="button" value="添加该cookie" onclick="add_()"/><input type="button" value="读取所有cookie" onclick="allCookie()"/><input type="button" value="读取该名称cookie" onclick="get_()"/><input type="button" value="删除该名称cookie" onclick="del_()"/> 
   </div> 
  </form> 
</body> 
</html>

document.cookie = "Test=cooo";
alert(document.cookie);