HTML stands for Hyper Text Markup Language. It is the standard markup language for creating web pages and web applications.
It is used to give meaning to text, images, and other content, and to specify how they should be displayed in a web browser.
To create an HTML file, you will need to use a text editor (such as Notepad or TextEdit) to write your HTML code. Save the file with an .html or .htm file extension.
Tags are used to define the structure of a web page. Tags are enclosed in angle brackets, and they come in pairs. The first tag in a pair is called the opening tag, and the second tag is called the closing tag.
The opening tag contains the name of the element, and the closing tag contains a forward slash before the element name.
<p>hello world</p>
No, not all HTML tags have an end tag. Some HTML tags have no end tag.
Some of them are following:<br>, <hr>, <img>, <input>, <link>, <meta>, <param>
To create a hyperlink in HTML, you will need to use the anchor tag <a> and specify the link in the href attribute.
<a href="https://www.google.com">Google</a>
XHTML is an XML-based markup language that is used to create web pages. It is a stricter version of HTML.
XHTML is more strict than HTML, and requires that all tags are closed and that all elements are properly nested.
Here is the example of XHTML:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>My XHTML Document</title>
</head>
<body>
<p>This is a paragraph.</p>
</body>
</html>
Here is the example of HTML:
<!DOCTYPE html>
<html>
<head>
<title>My HTML Document</title>
</head>
<body>
<p>This is a paragraph.</p>
</body>
</html>
To create a table in HTML, you can use the table element and its related elements, such as `thead`, `tbody`, and `td`.
Here's an example of how you might create a table in HTML:
<table>
<thead>
<tr>
<th>Firstname</th>
<th>Lastname</th>
<th>Age</th>
</tr>
</thead>
<tbody>
<tr>
<td>Jill</td>
<td>Smith</td>
<td>50</td>
</tr>
<tr>
<td>Eve</td>
<td>Jackson</td>
<td>94</td>
</tr>
</tbody>
</table>
To add an image in HTML, you will need to use the image tag <img> and specify the image source in the src attribute.
<img
src="https://images.google.com/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png"
/>
To create a form in HTML, you will need to use the form tag <form> and specify the form fields in the <input> tag.
You will also need to specify the form action in the action attribute.
<form action="/action_page.php">
First name:<br />
<input type="text" name="firstname" value="Mickey" />
<br />
Last name:<br />
<input type="text" name="lastname" value="Mouse" />
<br /><br />
<input type="submit" value="Submit" />
</form>
To create a list in HTML, you will need to use the list tag <ul> and specify the list items in the <li> tag.
<ul>
<li>HTML</li>
<li>CSS</li>
<li>JavaScript</li>
</ul>
To create a heading in HTML, you will need to use the heading tag <h1> to <h6> and specify the heading text in the <h1> tag.
<h1>Heading 1</h1>
<h2>Heading 2</h2>
<h3>Heading 3</h3>
<h4>Heading 4</h4>
<h5>Heading 5</h5>
<h6>Heading 6</h6>
The id attribute is used to specify a unique id for an HTML element.
The class attribute is used to specify one or more class names for an HTML element.
The id attribute is used to point to a style in a style sheet, and the class attribute can be used to point to a style in a style sheet, or to be used by a script.
Semantic tags are HTML tags that have a specific meaning.
For example, the <header> tag defines a header for a document or a section.
/* header of the page */
<header>
<h1>My Website</h1>
</header>
/* navigation bar */
<nav>
<a href="/html/">HTML</a> | <a href="/css/">CSS</a> |
<a href="/js/">JavaScript</a> |
<a href="/jquery/">jQuery</a>
</nav>
/* main content */
<section>
<h1>HTML</h1>
<p>HTML is a markup language for describing web documents.</p>
</section>
/* footer of the page */
<footer>
<p>Posted by: Hege Refsnes</p>
</footer>
A URL is encoded in HTML to make it safe to use in a web page.
For example, if you have a URL that contains a space, you will need to encode the space as %20 to make it safe to use in a web page.
The !DOCTYPE html declaration is not an HTML tag. It is an instruction to the web browser about what version of HTML the page is written in.
The !DOCTYPE html declaration must only be at the top of the page (before any HTML tags).
The `async` attribute is a boolean attribute.
When present, it specifies that the script is executed asynchronously as soon as it is available.
The `defer` attribute is a boolean attribute.
When present, it specifies that the script is executed when the page has finished parsing.
HTML elements are the content between the opening and closing tags.
HTML tags are the opening and closing tags.
An empty element is an element with no content.
For example, the <br> tag defines a single line break.
Entities are characters that are not allowed in HTML.
For example, the < character is not allowed in HTML. You will need to use the < entity instead.
The multipart/form-data value is used to specify that the form data should be encoded as MIME data.
The multipart/form-data value is only used when themethod attribute is set to post.
The <head> section contains meta information about the HTML document.
The <head> section is a container for all the head elements, including a title for the document, scripts, styles, meta information, and more.
The `GET` method requests data from a specified resource.
The `POST` method submits data to be processed to a specified resource.
The `accesskey` attribute specifies a shortcut key to activate/focus an element.
The `accesskey` attribute is used to provide a keyboard shortcut to an element.
Some common layout frameworks for HTML and CSS are:
- Bootstrap
- Foundation
- Materialize
- UIkit
- W3.CSS
There are three types of lists in HTML:
- Ordered list - <ol>
- Unordered list - <ul>
- Description list - <dl>
these are the differences between block-level and inline elements:
| Block-level element | Inline element |
|---|---|
| Block-level elements start on a new line and take up the full width available (stretches out to the left and right as far as it can). | Inline elements do not start on a new line and only take up as much width as necessary. |
| Block-level elements can contain inline elements and other block-level elements. | Inline elements can only contain text and other inline elements. |
| Examples of block-level elements are <div>, <h1>, <p>, <form>, and <li>. | Examples of inline elements are <span>, <a>, <b>, <img>, and <input>. |
To create a form in HTML, you will need to use the form tag <form> and specify the form fields in the <input> tag.
You will also need to specify the form action in the action attribute.
The different types of form elements available are:
<input type="text">- creates a single-line text input field<input type="password">- creates a password field<input type="radio">- creates a radio button<input type="checkbox">- creates a checkbox<input type="submit">- creates a submit button<input type="reset">- creates a reset button<input type="button">- creates a button<input type="file">- creates a file upload field<input type="hidden">- creates a hidden input field<input type="image">- creates an image input field<input type="email">- creates an email input field<input type="number">- creates a number input field<input type="range">- creates a range input field<input type="search">- creates a search input field<input type="tel">- creates a telephone input field<input type="url">- creates a URL input field<input type="date">- creates a date input field<input type="time">- creates a time input field
To insert an image in HTML, you will need to use the image tag <img> and specify the image source in the src attribute.
You will also need to specify the image dimensions in the width and height attributes.
<img src="https://www.google.com" width="100" height="100" />
The div element is a block-level element and the span element is an inline element.
| div | span |
|---|---|
| Block-level element | Inline element |
| Used to group block-level or inline elements | Used to group inline elements |
| Can be styled with CSS | Can be styled with CSS |
| Can contain block-level and inline elements | Can contain inline elements |
To use the style attribute in HTML to apply inline styles to an element, you will need to specify the style attribute in the element and specify the style properties in the attribute.
/*This is blue paragraph with some left margin*/
<p style="color:blue;margin-left:20px;">hello world!</p>
To use the class and id attributes in HTML to apply styles using CSS, you will need to specify the class and id attributes in the element and specify the style properties in the CSS file.
<p class="red">This is paragraph</p>
<p id="red">This is paragraph</p>
.red {
color: red;
}
#red {
color: red;
}
To create a numbered or bulleted list in HTML, you will need to use the ordered list tag <ol> and unordered list tag <ul> and specify the list items in the <li> tag.
<ol>
<li>Coffee</li>
<li>Tea</li>
<li>Milk</li>
</ol>
<ul>
<li>Coffee</li>
<li>Tea</li>
<li>Milk</li>
</ul>
To use the details and summary elements to create an expandable section in HTML, you will need to use the details tag <details> and summary tag <summary>.
<details>
<summary>Click to expand</summary>
<p>Some text in the details element.</p>
</details>
The meta tag is used to provide metadata about the HTML document. Metadata will not be displayed on the page but will be machine parsable.
<meta charset="UTF-8" />
<meta name="description" content="Free Web tutorials" />
<meta name="keywords" content="HTML,CSS,XML,JavaScript" />
<meta name="author" content="John Doe" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
The iframe tag is used to embed another document within the current HTML document.
<iframe src="https://www.w3schools.com"></iframe>
To use the Web Workers API to run background tasks in a web page, you will need to create a new Worker object and specify the script to be run in the worker.
<script>
// Create a new worker
var worker = new Worker("demo_workers.js");
// Send message to worker
worker.postMessage("Hello World");
// Receive message from worker
worker.onmessage = function(event) {
document.getElementById("result").innerHTML = event.data;
}
</script>
To use the HTML5 Geolocation API to access the user's location, you will need to use the navigator.geolocation object and specify the function to be executed when the location is available.
<script>
var x = document.getElementById("demo");
function getLocation() {
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(showPosition);
} else {
x.innerHTML = "Geolocation is not supported by this browser.";
}
}
function showPosition(position) {
x.innerHTML = "Latitude: " + position.coords.latitude +
"<br>Longitude: " + position.coords.longitude;
}
</script>
The figure tag is used to specify self-contained content, like illustrations, diagrams, photos, code listings, etc.
<figure>
<img src="img_mountains.jpg" alt="Mountains" style="width:100%" />
<figcaption>Fig.1 - A picture of a mountain.</figcaption>
</figure>
The datalist tag is used to provide a predefined list of values for an input element.
<input list="browsers" />
<datalist id="browsers">
<option value="Internet Explorer"></option>
<option value="Firefox"></option>
<option value="Chrome"></option>
<option value="Opera"></option>
<option value="Safari"></option>
</datalist>
To use the contenteditable attribute in HTML, you will need to specify the contenteditable attribute in the element and set it to true.
The contenteditable attribute is used to make an element editable.
<p contenteditable="true">This is a paragraph.</p>
To implement drag and drop functionality in HTML, you will need to use the dragstart, drag, dragenter, dragleave, dragover, drop, and dragend events.
The dragstart event is fired when the user starts dragging an element.
The drag event is fired when an element or text selection is being dragged.
The dragenter event is fired when a dragged element or text selection enters a valid drop target.
The dragleave event is fired when a dragged element or text selection leaves a valid drop target.
The dragover event is fired when an element or text selection is being dragged over a valid drop target.
<div id="div1" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
<div id="div2" draggable="true" ondragstart="drag(event)"></div>
<script>
function allowDrop(ev) {
ev.preventDefault();
}
function drag(ev) {
ev.dataTransfer.setData("text", ev.target.id);
}
function drop(ev) {
ev.preventDefault();
var data = ev.dataTransfer.getData("text");
ev.target.appendChild(document.getElementById(data));
}
</script>
For more information, Open this link
To optimize the performance of a webpage, you will need to use the following techniques:
- Use a CDN to host static files.
- Minify and compress static files.
- Use a service worker to cache static files.
- Use a preprocessor to compile CSS and JavaScript.
- Use a bundler to bundle CSS and JavaScript.
- Use a minifier to minify CSS and JavaScript and remove unused code.
- Use a linter to check for errors in CSS and JavaScript.
- Use a compiler to compile TypeScript to JavaScript.
- Lazy load images and videos.
To use the canvas element in HTML to create graphics and animations using JavaScript, you will need to use the canvas tag <canvas> and specify the canvas id in the id attribute.
<canvas
id="myCanvas"
width="200"
height="100"
style="border:1px solid #000000;"
>
Your browser does not support the HTML5 canvas tag.</canvas
>
var c = document.getElementById("myCanvas");
var ctx = c.getContext("2d");
ctx.moveTo(0, 0);
ctx.lineTo(200, 100);
ctx.stroke();
To use the audio and video elements in HTML to embed media files on a webpage, you will need to use the audio and video tags <audio> and <video> and specify the media source in the src attribute.
<audio src="audio.mp3" controls></audio>
<video src="video.mp4" controls></video>
To use the svg element in HTML to create scalable vector graphics, you will need to use the svg tag <svg> and specify the svg id in the id attribute.
<svg id="svg"></svg>
const svg = document.getElementById("svg");
const rect = document.createElementNS("http://www.w3.org/2000/svg", "rect");
rect.setAttribute("x", "10");
rect.setAttribute("y", "10");
rect.setAttribute("width", "100");
rect.setAttribute("height", "100");
rect.setAttribute("fill", "red");
svg.appendChild(rect);
To use the web workers API in JavaScript to run tasks in the background and improve the performance of a webpage, you will need to create a web worker using the Worker() constructor and specify the script file in the constructor.
const worker = new Worker("worker.js");
worker.postMessage("Hello World");
worker.onmessage = function (event) {
console.log(event.data);
};
Yes, you can use the data and value attributes to provide additional information about an HTML element.
The data attribute is used to store custom data private to the page or application.
The value attribute is used to specify the value of an input element or value of a option element in a select element.
<!-- The data-* attributes is used to store custom data private to the page or application. -->
<p data-info="This is a paragraph.">This is a paragraph.</p>
<!-- value attribute is used to store a default value for the input field. -->
<input type="text" name="firstname" value="Mickey" />
<!-- The value attribute is used in the <option> tag to specify the default value of a dropdown list. -->
<select name="cars">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="mercedes">Mercedes</option>
<option value="audi">Audi</option>
</select>
To use the dialog element to create a dialog box or popup window in HTML, you will need to use the dialog tag <dialog> and specify the dialog id in the id attribute.
<!-- Create the dialog element -->
<dialog id="myDialog">
<!-- Add content to the dialog -->
<h1>Hello!</h1>
<p>This is a modal dialog.</p>
<!-- Add buttons to the dialog -->
<button id="closeBtn">Close</button>
</dialog>
<!-- Create the button that opens the dialog -->
<button id="openBtn">Open Dialog</button>
<script>
// Get the dialog element
var dialog = document.getElementById('myDialog');
// Get the button that opens the dialog
var btn = document.getElementById("openBtn");
// Get the button that closes the dialog
var close_btn = document.getElementById("closeBtn");
// When the user clicks the button, open the dialog
btn.onclick = function() {
dialog.show();
}
// When the user clicks on button, close the dialog
close_btn.onclick = function() {
dialog.close();
}
</script>
To use the HTML5 WebRTC API for real-time peer-to-peer communication, you will need to use the RTCPeerConnection constructor to create a peer connection and the getUserMedia() method to get the local media stream.
<script>
var constraints = { audio: true, video: { width: 1280, height: 720 } };
navigator.mediaDevices.getUserMedia(constraints)
.then(function(mediaStream) {
var video = document.querySelector('video');
video.srcObject = mediaStream;
video.onloadedmetadata = function(e) {
video.play();
};
}
</script>