封装cookie localStorage sessionStorage

 var cookie = function(name, value, options) {
        if (typeof value !== 'undefined') {
            options = options || {};
            if (value === null) {
                value = '';
                options = $.extend({}, options);
                options.expires = -;
            }
            var expires = '';
            if (options.expires && (typeof options.expires === 'number' || options.expires.toUTCString)) {
                var date;
                if (typeof options.expires === 'number') {
                    date = new Date();
                    date.setTime(date.getTime() + (options.expires *  *  *  * ));
                } else {
                    date = options.expires;
                }
                expires = '; expires=' + date.toUTCString();
            }
            var path = options.path ? '; path=' + (options.path) : ';path=/';
            var domain = options.domain ? '; domain=' + (options.domain) : '';
            var secure = options.secure ? '; secure' : '';
            document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join('');
        } else {
            var cookieValue = null;
            if (document.cookie && document.cookie !== '') {
                var cookies = document.cookie.split(';');
                for (var i = ; i < cookies.length; i++) {
                    var cookie = $.trim(cookies[i]);
                    if (cookie.substring(, name.length + ) === (name + '=')) {
                        cookieValue = decodeURIComponent(cookie.substring(name.length + ));
                        break;
                    }
                }
            }
            return cookieValue;
        }
    }
    var removeCookie = function(key) {
        $.cookie(key, '', {
            expires: -
        });
    }

    var storage = function(st, key, value, expires) {
            if (st == 'l') {
                st = window.localStorage;
                expires = expires || ;
            } else {
                st = window.sessionStorage;
                expires = expires || ;
            }
            if (typeof value != 'undefined') {
                try {
                    return st.setItem(key, JSON.stringify({
                        data: value,
                        expires: new Date().getTime() + expires *  *
                    }));
                } catch (e) {}
            } else {
                var result = JSON.parse(st.getItem(key) || '{}');
                if (result && new Date().getTime() < result.expires) {
                    return result.data;
                } else {
                    st.removeItem(key);
                    return null;
                }
            }
        }