Javascript event question _ javascript skills

We all know that in the DOM event model, there are two stages: capture and bubbling, while in the IE event model, there is only the bubble stage. The Event Response Function written in html is executed only in the bubble stage. The Code is as follows:

Hi!

1. When you place the cursor over it, alert ('World') and alert ('hello') are executed in sequence. We can see that the event response function is executed in the bubble stage, that is, DOM-compatible browsers are not executed during the capture phase. Therefore, the Event Response Function written in html is executed only in the bubble stage.
2. When you move the mouse over p to span, alert ('out _ p'), alert ('World'), alert ('hello'), and '), this indicates that although span is in p, when you move the mouse from p to span, it is also to move the mouse out of p.