试着用

$(window).unload(function(){
  localStorage.clear();
});

希望这对你有用

    if(localStorage.getItem("visit") === null) {
      localStorage.setItem('visit', window.location.hostname);
      console.log(localStorage.getItem('visit'));
    } 
      else if(localStorage.getItem('visit') == 'localhost'){
            console.log(localStorage.getItem('visit'));
      }
    else {
     console.log(localStorage.getItem('visit'));
    }
   $(document).ready(function(){
      $("#clickme").click(function(){
         localStorage.setItem('visit', '0');
      });
   });  
   window.localStorage.removeItem('visit');

sessionStorage使用

sessionStorage对象与localStorage对象相同，只是它只存储一个会话的数据。当用户关闭浏览器窗口时，数据将被删除。

下面的例子统计用户在当前会话中点击按钮的次数:

例子

if (sessionStorage.clickcount) {
    sessionStorage.clickcount = Number(sessionStorage.clickcount) + 1;
} else {
    sessionStorage.clickcount = 1;
}
document.getElementById("result").innerHTML = "You have clicked the button " +
sessionStorage.clickcount + " time(s) in this session.";

这是一个老问题，但上面的答案似乎都不完美。

如果您希望存储身份验证或任何敏感信息，这些信息仅在浏览器关闭时被销毁，那么您可以依赖sessionStorage和localStorage进行跨选项卡消息传递。

基本上，这个想法是:

You bootstrap from no previous tab opened, thus both your localStorage and sessionStorage are empty (if not, you can clear the localStorage). You'll have to register a message event listener on the localStorage. The user authenticate/create a sensitive info on this tab (or any other tab opened on your domain). You update the sessionStorage to store the sensitive information, and use the localStorage to store this information, then delete it (you don't care about timing here, since the event was queued when the data changed). Any other tab opened at that time will be called back on the message event, and will update their sessionStorage with the sensitive information. If the user open a new tab on your domain, its sessionStorage will be empty. The code will have to set a key in the localStorage (for exemple: req). Any(all) other tab will be called back in the message event, see that key, and can answer with the sensitive information from their sessionStorage (like in 3), if they have such.

请注意，此方案不依赖于窗口。Onbeforeunload事件是脆弱的(因为浏览器可以关闭/崩溃而不触发这些事件)。此外，敏感信息存储在localStorage上的时间非常短(因为您依赖于跨选项卡消息事件的transcients更改检测)，因此此类敏感信息不太可能泄漏到用户的硬盘驱动器上。

下面是这个概念的演示:http://jsfiddle.net/oypdwxz7/2/

我不认为这里提出的解决方案是100%正确的，因为窗口。onbeforeunload事件不仅在浏览器/选项卡关闭时被调用(这是必需的)，而且在所有其他几个事件上也被调用。(可能不需要)

有关可以触发window.onbeforeunload的事件列表的更多信息，请参阅此链接

http://msdn.microsoft.com/en-us/library/ms536907 (VS.85) . aspx

localStorage.removeItem(key);  //item

localStorage.clear(); //all items