js的事件委託機制

Question

var list = document.getElementById("myList"); EventUtil.addHandler(list,"click",function(event){ event = EventUtil.getEvent(event); var target = EventUtil.getTarget(event); switch(target.id){ case"doSomething": document.title = "I change the document's title"; break; case"goSomewhere": loaction.href = "https://zhidao.baidu.com/question/267743089103468925.html?qbl=relate_question_0&word=js%CA%C2%BC%FE%CE%AF%C5%C9" break; case"sayHi": alert("Hello World!!!"); break; } })對於事件委託這一塊一直不是很理解，說是用到了事件冒泡，但是事件委託綁定的不是dom樹種最高層次上添加處理程序，怎麼事件冒泡的它的子元素,求大佬解答