代码示例:(标识:eg_js_intro_inner_html)
<!DOCTYPE html>
<html>
<body>

<h2>JavaScript 能做什么</h2>

<p id="demo">JavaScript 能够改变 HTML 内容。</p>

<button type="button" onclick='document.getElementById("demo").innerHTML = "Hello JavaScript!"'>点击我!</button>

</body>
</html>
运行结果: