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>
输出结果: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>
输出结果：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>
输出结果：My First Web Page
My First Paragraph.
转载自：http://holysonll.blog.163.com/blog/static/21413909320134111054352/