基础不牢，房塌屋倒。javascript如果没有把基础知识掌握牢固的话，可能在实践中遇见一些本来很简单的实现方式，却劳师动众的用各种组合封装函数来实现一个简单的功能。
function() {}()
(function() { const now = new Date(); const year = now.getFullYear(); const month = now.getMonth()+1; const day = now.getDate(); $("#nowDate").html(year+"年"+month+"月"+day+"日"); })();
等同于
//获取当天日期 $(function () { const now = new Date(); const year = now.getFullYear(); const month = now.getMonth() + 1; const day = now.getDate(); $("#nowDate").html(year + "年" + month + "月" + day + "日"); });
function showTime()
//获取当天日期 function showTime() { const now = new Date(); const year = now.getFullYear(); const month = now.getMonth() + 1; const day = now.getDate(); $("#nowDate").html(year + "年" + month + "月" + day + "日"); } showTime();
等同于
//获取当天日期 var showTime = function () { const now = new Date(); const year = now.getFullYear(); const month = now.getMonth() + 1; const day = now.getDate(); $("#nowDate").html(year + "年" + month + "月" + day + "日"); } showTime();
Done！
![[JS]同事：这次就算了，下班回去赶紧补补内置函数，再犯肯定被主管骂](https://ucc.alicdn.com/3mfxe2r26qbaq/developer-article1635463/20241109/c55917b4a28342b78633c9da58d86e30.png?x-oss-process=image/resize,h_160,m_lfit)