先判断jq是否被加载if (typeof window.jQuery == “undefined”) {//未引用Jquery} else {//引用了Jquery}再加载jqif (typeof window.jQuery == ‘undefined’) {var fileref = document.createElement(‘script’); //创建标签fileref.setAttribute(“type”, “text/javascript”); //定义属性type的值为text/javascriptfileref.setAttribute(“src”, “/js/jq.js”); &nbs...