I asked this question once before but did not get the result. Maybe my description was not clear enough. Now I have reorganized my thoughts. The details are as follows:

function demo(){
    // 各种实现
}
demo();    // 我希望它默认就执行一次，所以就这么调用了。

窗口事件：
$(window).resize(function(){
    demo();    // 这里也需要根据条件调用demo函数
});

The question is, is there a way to make the demo execute automatically for the first time? And then it can be called elsewhere? How to optimize such a code body, exclude: arguments.callee, please give me some advice... Thank you in advance.