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');

你可以在JavaScript中使用beforeunload事件。

使用JavaScript，你可以这样做:

window.onbeforeunload = function() {
  localStorage.removeItem(key);
  return '';
};

这将在浏览器窗口/选项卡关闭之前删除键，并提示您确认关闭窗口/选项卡操作。我希望这能解决你的问题。

注意:onbeforeunload方法应该返回一个字符串。

在这个问题被提出6年后，我发现这个问题仍然没有足够的答案;这应该实现以下所有:

关闭浏览器(或域的所有选项卡)后清除本地存储 如果至少有一个选项卡保持活动状态，则跨选项卡保留本地存储 重新加载单个选项卡时保留本地存储

在每个页面加载开始时执行这段javascript代码，以实现上述目标:

((nm,tm) => {
    const
            l = localStorage,
            s = sessionStorage,
            tabid = s.getItem(tm) || (newid => s.setItem(tm, newid) || newid)((Math.random() * 1e8).toFixed()),
            update = set => {
                let cur = JSON.parse(l.getItem(nm) || '{}');
                if (set && typeof cur[tabid] == 'undefined' && !Object.values(cur).reduce((a, b) => a + b, 0)) {
                    l.clear();
                    cur = {};
                }
                cur[tabid] = set;
                l.setItem(nm, JSON.stringify(cur));
            };
    update(1);
    window.onbeforeunload = () => update(0);
})('tabs','tabid');

编辑:这里的基本思想如下:

When starting from scratch, the session storage is assigned a random id in a key called tabid The local storage is then set with a key called tabs containing a object those key tabid is set to 1. When the tab is unloaded, the local storage's tabs is updated to an object containing tabid set to 0. If the tab is reloaded, it's first unloaded, and resumed. Since the session storage's key tabid exists, and so does the local storage tabs key with a sub-key of tabid the local storage is not cleared. When the browser is unloaded, all session storage will be cleared. When resuming the session storage tabid won't exists anymore and a new tabid will be generated. Since the local storage does not have a sub-key for this tabid, nor any other tabid (all session were closed), it's cleared. Upon a new created tab, a new tabid is generated in session storage, but since at least one tabs[tabid] exists, the local storage is not cleared

for (let i = 0; i < localStorage.length; i++) {
    if (localStorage.key(i).indexOf('the-name-to-delete') > -1) {
        arr.push(localStorage.key(i));
    }
}

for (let i = 0; i < arr.length; i++) {
    localStorage.removeItem(arr[i]);
}

8.5年过去了，最初的问题一直没有得到答案。

当浏览器关闭时，没有一个标签。

这个基本代码片段将为您提供两全其美的服务。仅在浏览器会话期间存在的存储(如sessionStorage)，但也可以在选项卡之间共享(localStorage)。

它完全通过localStorage来实现这一点。

function cleanup(){
    // place whatever cleanup logic you want here, for example:
    // window.localStorage.removeItem('my-item')
}

function tabOpened(){
    const tabs = JSON.parse(window.localStorage.getItem('tabs'))
    if (tabs === null) {
        window.localStorage.setItem('tabs', 1)
    } else {
        window.localStorage.setItem('tabs', ++tabs)
    }
}

function tabClosed(){
    const tabs = JSON.parse(window.localStorage.getItem('tabs'))
    if (tabs === 1) {
        // last tab closed, perform cleanup.
        window.localStorage.removeItem('tabs')
        cleanup()
    } else {
        window.localStorage.setItem('tabs', --tabs)
    }
}

window.onload = function () {
    tabOpened();
}

window.onbeforeunload = function () {
    tabClosed();
}

您可以简单地使用sessionStorage。因为sessionStorage允许在浏览器窗口关闭时清除所有键值。

看这里:SessionStorage- MDN