What is the first line of code in html5
In html5, the first line of code is "<!DOCTYPE>"; html5 document codes all start with "<!DOCTYPE>" as the first line. This code is a standard and universal The document type declaration of the markup language is used to tell the browser the version of the HTML code written in the page so that the browser can render it correctly.
The operating environment of this tutorial: windows10 system, html5 version, Dell G3 computer.
The first line of code of html5
<!DOCTYPE>
Any HTML document is the first line of code starting with the <!DOCTYPE> tag. This code will tell the browser the version of the HTML code written in the page so that the browser can render it correctly. In this sense, <!DOCTYPE> is not an HTML tag.
HTML 4.01 version of <!DOCTYPE> looks like this
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
The <!DOCTYPE> declared in our sample file is HTML5, which is the latest standard for HTML. It is more concise and easier to read than the previous version.
!DOCTYPE does not belong to the HTML (an application under the Standard Universal Markup Language) tag. It is a document type declaration of the Standard Universal Markup Language. In HTML, it tells the browser the version of the markup used to write the page.
The<!DOCTYPE> declaration must be on the first line in the HTML5 document, before the tag. This tag tells the browser the HTML specification used by the document.
It is very important to specify !DOCTYPE in all HTML documents so that the browser understands the expected document type.
The !DOCTYPE in HTML 4.01 requires a reference to the DTD because HTML 4.01 is based on the Standard Universal Markup Language. HTML 5 is based on XML (a subset of the Standard Universal Markup Language), so there is no need to reference a DTD, but a !DOCTYPE is needed to regulate browser behavior (let browsers run the way they should).
Examples are as follows:
HTML5 document with the correct document type (!DOCTYPE):
<!DOCTYPE HTML> <html> <head> <title>文档的题目</title> </head> <body>文档的内容</body> </html>
Recommended tutorial: "html video tutorial 》
The above is the detailed content of What is the first line of code in html5. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



Guide to Table Border in HTML. Here we discuss multiple ways for defining table-border with examples of the Table Border in HTML.

Guide to HTML margin-left. Here we discuss a brief overview on HTML margin-left and its Examples along with its Code Implementation.

This is a guide to Nested Table in HTML. Here we discuss how to create a table within the table along with the respective examples.

Guide to HTML Table Layout. Here we discuss the Values of HTML Table Layout along with the examples and outputs n detail.

Guide to HTML Input Placeholder. Here we discuss the Examples of HTML Input Placeholder along with the codes and outputs.

Guide to the HTML Ordered List. Here we also discuss introduction of HTML Ordered list and types along with their example respectively

Guide to Moving Text in HTML. Here we discuss an introduction, how marquee tag work with syntax and examples to implement.

Guide to HTML onclick Button. Here we discuss their introduction, working, examples and onclick Event in various events respectively.
