js清除指定的cookie

function deleteCookie(name, path, domain) {
    if (getCookie(name)) {
        document.cookie = name + "=" +
            (path ? ";path=" + path : "") +
            (domain ? ";domain=" + domain : "") +
            ";expires=Thu, 01 Jan 1970 00:00:00 GMT";
    }
}

function getCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) === ' ') c = c.substring(1, c.length);
        if (c.indexOf(nameEQ) === 0) return c.substring(nameEQ.length, c.length);
    }
    return null;
}

// 使用示例
deleteCookie('cookieName', '/', 'example.com');