api的应用场景是:查询元素是否含有指定的属性。
关于ZYC.dom.g的资料:http://zhangyaochun.iteye.com/blog/1439262
/* *hasAttr --- check the element if it has the name attribute* *@function* *@param {HTMLElement} element* *@param {String} name the name that looked for* *@return {Boolean}* */ ZYC.dom.hasAttr = function(element,name){ element = ZYC.dom.g(element); var attr = element.attributes.getNamedItem(name); return !!(attr && attr.specified); };