2016-9-8 about <! DOCTYPE html>

<! DOCTYPE html>

function :

Declare the type of document resolution (DOCUMENT.COMPATMODE) to avoid the bizarre behavior of the browser.

Avoid page-style bugs in different browsers, browser-compatible issues.

Two ways to page rendering (Document.compatmode):

Quirks mode (BACKCOMPAT): The browser uses its own quirks mode to render the page (default)

Standard mode (CSS1COMPAT): Browsers use the Web mode to render pages

If we don't <! DOCTYPE html> to make a statement, the page defaults to the weird mode (BACKCOMPAT). This will show different browser pages.

We declare the <! DOCTYPE html>, the page will render the page in a Web-based mode, avoiding different styles of bugs in different browsers.

How to use:

Case insensitive

1. Add <! to the first line of the HTML page DOCTYPE html>

2.JSP page, add the next line of <% @page%>

2016-9-8 about <! DOCTYPE html>