innerHTML
<!DOCTYPE html>
<html>
<body>
<h1>My First Web Page</h1>
<p id="demo">My First Paragraph.</p>
<script>
document.getElementById("demo").innerHTML="<h1>My First JavaScript</h1>";
</script>
</body>
</html>
My First Web Page
My First Javascript
innerText<!DOCTYPE html>
<html>
<body>
<h1>My First Web Page</h1>
<p id="demo">My First Paragraph.</p>
<script>
document.getElementById("demo").innerText="<h1>My First JavaScript</h1>";
</script>
</body>
</html>
My First Web Page
<h1>My First Javascript</h1>
value<!DOCTYPE html>
<html>
<body>
<h1>My First Web Page</h1>
<p id="demo">My First Paragraph.</p>
<script>
document.getElementById("demo").value="<h1>My First JavaScript</h1>";
</script>
</body>
</html>
My First Web Page
My First Paragraph.
转载自：http://holysonll.blog.163.com/blog/static/21413909320134111054352/