如果未找到 cookie，则重定向到页面

Question

例如，如果是 cookie

visited

没有找到，是否可以让页面重定向到

/welcome

我从这个开始：

    function getCookie(visited) {
    var dc = document.cookie;
    var prefix = visited + "=";
    var begin = dc.indexOf("; " + prefix);
    if (begin == -1) {
        begin = dc.indexOf(prefix);
        if (begin != 0) return null;
    }
    else
    {
        begin += 2;
        var end = document.cookie.indexOf(";", begin);
        if (end == -1) {
        end = dc.length;
        }
    }
    return decodeURI(dc.substring(begin + prefix.length, end));
} 

function doSomething() {
    var myCookie = getCookie("visited");

    if (myCookie == null) {
        window.location.href = '/welcome';
    }
    else {
    }
}

我这样做是否正确，因为它在我的网站上无法正常工作。

Answer 1

试试 PHP：

if (!isset($_COOKIE['visited'])) {
    header("Location: page.php");
}

Answer 2

尝试使用下面的这个 checkCookie 函数

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 + ";path=/";
}  

function getCookie(cname) {
    var name = cname + "=";
    var decodedCookie = decodeURIComponent(document.cookie);
    var ca = decodedCookie.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) == 0) {
            return c.substring(name.length, c.length);
        }
    }
    return "";
}

function checkCookie() {
    var visited = getCookie("visited");
    if (visited != "") {
        // do whatever
    } else {
        setCookie("visited", "true", 30);
        window.location.href = '/welcome';
    }
}

更多信息，我建议访问W3Schools或MDN