Javascript 每个浏览器会话弹出一次cookie

我有一个非常简单的弹出窗口，我想设置一个cookie，因此当访问者第一次访问页面/类别时，他将能够看到弹出窗口，如果他导航出页面并返回，弹出窗口将不会出现，直到他结束会话（关闭浏览器）。谢谢

类似的内容（未测试的代码）：

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可能与我添加的代码重复：我添加了1分钟以检查它是否有效，但没有。我做错了什么？var createCookie=Openpopup（名称、值、天数）{var expires；if（天数）{var date=new date（）；date.setTime（date.getTime（）+（60*1000））；expires=“；expires=“+date.togmString（）；}否则{expires=“；}document.cookie=name+”=“+value+expires+”；“path=/”；}您应该阅读一些Javascript教程。当你对你正在做的事情有了一个基本的了解后再来。太棒了！它的效果很好。谢谢你花时间解释。这意味着很多。我用一分钟（*60*1000）测试了它，效果如预期。我的问题是-有没有办法为一个浏览器会话设置cookie。每个浏览器会话只能出现一次弹出窗口，如果访问者关闭它并重新打开窗口，它必须再次出现。再次感谢弗朗西斯科，谢谢你，先生@crv是否尝试忽略了days参数<代码>createCookie（“你以前在这里吗”，“是”）<script type="text/javascript"> var link; var element; t = setTimeout(openPopUp, 3000); function openPopUp() { element = document.getElementById("background"); element.style.display = "block"; element = document.getElementById("popup"); element.style.display = "block"; } function closePopUp() { element = document.getElementById("popup"); element.style.display = "none"; element = document.getElementById("background"); element.style.display = "none"; } </script>

var createCookie = Openpopup(name, value, days) {
    var expires;
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (60 * 1000));
        expires = ";
        expires = " + date.toGMTString();
    } else {
        expires = "";
    }
    document.cookie = name + "=" + value + expires + ";
    path=/";
} 

var link;

// ....


if(getCookie("was_here_before")=="") {
    setTimeout(openPopUp, 3000);
    createCookie("was_here_before", "yes", 1);
}

// ....



// these are from SO answer in first comment by Sverri M. Olsen
// [ http://stackoverflow.com/questions/4825683/how-do-i-create-and-read-a-value-from-cookie ]



function createCookie(name, value, days) {
    var expires;
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        expires = "; expires=" + date.toGMTString();
    }
    else {
        expires = "";
    }
    document.cookie = name + "=" + value + expires + "; path=/";
}

function getCookie(c_name) {
    if (document.cookie.length > 0) {
        c_start = document.cookie.indexOf(c_name + "=");
        if (c_start != -1) {
            c_start = c_start + c_name.length + 1;
            c_end = document.cookie.indexOf(";", c_start);
            if (c_end == -1) {
                c_end = document.cookie.length;
            }
            return unescape(document.cookie.substring(c_start, c_end));
        }
    }
    return "";
}


// ....


function openPopUp(url) {
    var element;
    link = url; // don't know what this is for
    element = document.getElementById("background");
    element.style.display = "block";
    element = document.getElementById("popup");
    element.style.display = "block";
}

function closePopUp() {
    var element;
    element = document.getElementById("popup");
    element.style.display = "none";
    element = document.getElementById("background");
    element.style.display = "none";
}