- Recognize basic HTML document structure
- Recognize HTML comments
- Describe the
headsection and its contents - Create an HTML document
Every HTML document has a specific set of required tags. Because these are required every time we create a web page, it is valuable to gain a more in-depth understanding of what these tags do, why they are useful, and how they work in context to the modern web.
We will be both reviewing setting up well-formed HTML documents and expanding a
bit on the DOCTYPE, html and head tags, as well as introducing how to add
comments within our HTML code.
If you haven't already, fork and clone this lesson into your local
environment. Navigate into its directory in the terminal, then run code . to
open the files in Visual Studio Code.
Let's start by adding the bare essentials of an HTML document to the provided
index.html file:
- A
DOCTYPEtag, which looks like this:<!DOCTYPE html> - Opening and closing
htmltags - Opening and closing
headtags nested inside thehtmltags - Opening and closing
bodytags nested inside thehtmltags
Note: Recall that best practice indicates that any HTML elements that are nested inside other HTML elements (i.e., between the opening and closing tags of another element) should be indented. It is not necessary to use indenting, either for the HTML to render properly or to pass the tests, but it's a good habit to get into. Go ahead and indent the
headandbodytags inside thehtmltags, if you haven't already.
If written correctly, running npm test now will pass three of the seven
tests:
has a DOCTYPE taghas opening and closing HTML tagshas <head> and <body> tags nested in the <html> tag
However you will not be done yet! We have to make all the tests pass in order to make the test code happy! Let's get to it!
Let's take a closer look at these tags.
At the top of every HTML document, you're always going to start off with the
same element, DOCTYPE. In the early days of the internet, there were fewer
standards, and it was important to declare the specific way we wanted browsers
to interpret the file at the top of each file. Netscape and Internet Explorer
would look for this declaration and handle the content differently depending on
what it found. These days, every current browser is compatible with HTML5, and
DOCTYPE is mainly used to tell the browser to render the page in standards
compliant mode.
The DOCTYPE element, as with all HTML, starts with a < and ends with a >.
Uniquely, the DOCTYPE tag starts with an exclamation point, !, followed by
DOCTYPE, then specifies which version of HTML we want to use. In HTML5, we
just write html and the browser interprets the rest of the document as HTML5.
The next element is also always required: <html>. This tells the browser that
everything that falls between the opening and closing html tags is to be
interpreted as HTML code.
One attribute that is important to include in the <html> tag is lang, which
declares what language the webpage is written in. In our case, writing in
English, we will use lang="en". This helps search engines to know what
language a page is written in. Google, for instance, can use the lang
attribute to know when to prompt users about translating web content.
<html lang="en"></html>Go ahead and add the language attribute to the html element. Now, if you run
the tests again, there should be four passing.
Sometimes we want to leave notes either for ourselves or for other developers inside of our HTML files. An example might be a brief explanation of what some part of the code is doing, or an important message or reminder. We can write comments by wrapping the text we want like so:
<!-- This is a comment! -->Text included in a comment will not be visible on the webpage, but will be
visible in the browser console and .html file.
Inside our html tags, we divide the page into two main sections, head, and
body, which both play unique roles. The remainder of our HTML lessons will
cover everything within the body section, but before we get there, there are
some additional bits of information we need to understand regarding the head.
The head section is not visible to a website visitor, but it contains a lot of
useful info about our webpage.
In the head section, we place a number of specific tags, most notably:
<link><title>
Let's look at each of them in turn:
The <link> tag is for importing files.
CAREFUL: It's easy to get confused here because web pages are full of links,
but also use a <link> tag. "Links" that you click on are located within the
<body> element. The <link> tags are located in the <head> element.
Most commonly, we'll use <link> to import CSS files. Go ahead and add the
following inside your head element (don't forget to indent!):
<link rel="stylesheet" type="text/css" href="style.css" >With a simple website, linking a single style sheet might work just fine. Often,
however, on fully developed websites, multiple style sheets are linked in the
head. For example, when doing the final polishing of a web site you might see
a series of <link> definitions like:
<link
rel="stylesheet"
href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css"
/>
<link rel="stylesheet" type="text/css" href="company.css" />
<link rel="stylesheet" type="text/css" href="engineering-department.css" />
<link rel="stylesheet" type="text/css" href="project-x-launch.css" />
<link rel="stylesheet" type="text/css" href="typography.css" />In this example we're getting some CSS information from the
Bootstrap project, we're integrating a company
style standard, an engineering style standard, a style motif for the launch of
"Project X" and then we're adding some specific rules about font display. You
can bring in a lot of information with the <link> tag!
This specific example aside, you'll be learning a lot more about linking files to create stylistic effect in later lessons.
Run the test again; you should now have five passing. Only two more to go!
One more common tag we find in the head is title. The title, as its name
implies, is where the title of the webpage should be entered. Text added inside
the title tags will appear up on your browser tab. Add the following title for
our index.html page:
<title>My Site Title</title>Notice that unlike the previous tags we've discussed, title has an opening and
closing tag. In most modern browsers, tabs are fairly small, so it is often best
to keep the title brief, or it will not be fully visible.
Adding the title should get the last two tests passing! Run the tests one last time to verify.
As always, don't forget to push up your code and submit it using CodeGrade once everything is passing.
In this lesson, we've reviewed the basics of document structure, as well as what
is typically contained within the head. Using the head section, we are able
to add relevant data about our webpage as a whole. As a bonus surprise, by
learning how to make our web pages search engine friendly, we've also dabbled
a bit into the basics of Search Engine Optimization! We are now ready to take a
deeper dive into the visual content of HTML pages.