cheatsheets

#判断是否是Array
function isArray(data) {
    return Array.isArray ? Array.isArray(data) : Object.prototype.toString.call(data) === '[object Array]';
}

#判断是否是 empty object {}
var isEmpty = function ua(data) {
    if (Object.keys)
        return Object.keys(data).length === 0;
    for (var wa in data)
        if (data.hasOwnProperty(wa))
            return false;
    return true;
};

#reference url: http://tech.colla.me/en/show/learn_from_facebook_pixel_js_code