1 addEventListener("click", function() {}, useCapture:false);
<!DOCTYPE html>
<html lang="en">
<head>
</head>
<body>
<div id="content" class="c1">
<a id="b">hhaha</a>
<a href="#!/fdaf">fda</a>
<a href="#!/fdaaa">fdf</a>
</div>
<script>
document.getElementById("b").addEventListener("click", function() {
//this.href = this.href.replace("?", "#");
console.log("inner");
},true);
window.addEventListener("hashchange", function() {
console.log(location.hash);
}, false);
document.getElementById("content").addEventListener("click", function() {
console.log("outer");
},true);
</script>
</body>
</html>
-------------->outer
-------------->inner
默认是不用捕获的。---------->由内向外
------------->inner
------------->outer
区别于xmlhttp.send("GET", url, async:true);--------->表示是否异步async
JavaScript中事件捕获(Event capturing)-------------->由外向内，事件冒泡(Event bubblin)---------->由内向外
原文：http://www.cnblogs.com/daishuguang/p/3983329.html