```html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>TItle of the document</title>
</head>
<body>
<input type="text" value="John Doe" disabled>
<input type="text" value=John Doe>
<input type="text" value="John Doe">
<input type="text" value='John Doe'>
</body>
</html>
运行结果如下:
![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/722200857536111.png "=600 #left")