<!DOCTYPE html>
<html>
<body>
<h1>JavaScript 正则表达式</h1>
<p>在字符串中搜索“w3School”，并显示匹配的位置：</p>
<p id="demo"></p>
<script>
var str = "Visit W3School!";
var n = str.search(/w3School/i);
document.getElementById("demo").innerHTML = n;
</script>
</body>
</html>