js对cookie的几个操作函数，网上找的（仅作备忘）

function getCookieVal(offset) {
    var endstr = document.cookie.indexOf(";", offset);
    if (endstr == - 1) {
        endstr = document.cookie.length;
    }
    return unescape(document.cookie.substring(offset, endstr));
}
function getCookie(name) {
    var arg = name + "=";
    var alen = arg.length;
    var clen = document.cookie.length;
    var i = 0;
    var j = 0;
    while (i < clen) {
        j = i + alen;
        if (document.cookie.substring(i, j) == arg) return getCookieVal(j);
        i = document.cookie.indexOf(" ", i) + 1;
        if (i == 0) break;
    }
    return null;
}
function deleteCookie(name) {
    var exp = new Date();
    var cval = getCookie(name);
    exp.setTime(exp.getTime() - 1);
    document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}
var gCookieExpDays = 80;
function setCookie(name, value) {
    var argv = setCookie.arguments;
    var argc = setCookie.arguments.length;
    var exp = (argc > 2) ? argv[2] : gCookieExpDays;
    var path = (argc > 3) ? argv[3] : null;
    var domain = (argc > 4) ? argv[4] : null;
    var secure = (argc > 5) ? argv[5] : false;
    var expires = new Date();
    deleteCookie(name);
    expires.setTime(expires.getTime() + (exp * 24 * 60 * 60 * 1000));
    document.cookie = name + "=" + value + "; expires=" + expires.toGMTString() + ((domain == null) ? "": ("; domain=" + domain)) + ((path == null) ? "": ("; path=" + path)) + ((secure == true) ? "; secure": "");
}

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