HTML Attributes

Common HTML Attributes

Let's take look at some of the most commonly used HTML attributes:

1. HTML alt Attribute

The alt attribute in HTML provides alternative text for an image if the image cannot be displayed. It improves accessibility and provides context for screen readers.

<html>
<head>
    <title>title>
head>
<body>
    <img src=
"https://media.geeksforgeeks.org/wp-content/cdn-uploads/Geek_logi_-low_res.png"
 style="width:350px; height:auto;" 
         alt="The Logo"><br>
body>
html>

2. HTML width and height Attribute

The width and height Attribute is used to adjust the width and height of an image(in pixels).

<html lang="en">
<head>
    <title>title>
head>
<body>
    <img src=
"https://media.geeksforgeeks.org/wp-content/cdn-uploads/Geek_logi_-low_res.png"
         width="300px"
         height="100px">
body>
html>

3. HTML id Attribute

The id attribute in HTML assigns a unique identifier to an element, allowing it to be targeted by CSS and JavaScript for styling and manipulation purposes.

<html>
<head>
    <style>
        #geeks {
            color: green;
        }
    style>
head>
<body>
    <h1 id="geeks">Welcome to GeeksforGeeksh1>
body>
html>

4. HTML title Attribute

The title attribute is used to explain an element by hovering the mouse over it. The behavior differs with various elements but generally, the value is displayed while loading or hovering the mouse pointer over it.

<html>
<head>
    <title>title>
head>
<body>
    <h3 title="Hello GeeksforGeeks">
        Hover to see the effect
    h3>
body>
html>

5. HTML href Attribute

The href attribute in HTML, used with the tag, specifies a link destination. Clicking the linked text navigates to this address. Adding `target="_blank"` opens it in a new tab.

<html>
<head>
    <title>title>
head>
<body>
    <a href="https://www.geeksforgeeks.org/">
        Click to open in the same tab
    a><br>
    <a href="https://www.geeksforgeeks.org/" 
       target="_blank">
        Click to open in a different tab
    a>
body>
html>

The style attribute is used to provide various CSS effects to the HTML elements such as increasing font-size, changing font-family, coloring, etc.

<html>
<head>
    <title>title>
head>
<body>
    <h2 style="font-family:Chaparral Pro Light;">
          Hello GeeksforGeeks.
      h2>
    <h3 style="font-size:20px;">
          Hello GeeksforGeeks.
      h3>
    <h2 style="color:#8CCEF9;">
          Hello GeeksforGeeks.
      h2>
    <h2 style="text-align:center;">
          Hello GeeksforGeeks.
      h2>
body>
html>

7. HTML lang attribute

The language is declared with the lang attribute. Declaring a language can be important for accessibility applications and search engines.

<html lang="en">

<head>
    <title>title>
    <style>
        body {
            text-align: center;
        }

        h1 {
            color: green;
        }

        .lang-info {
            font-style: italic;
        }
    style>
head>
<body>
    <h1>GeeksforGeeksh1>
    <h2>lang attributeh2>
    <p lang="en">
        A computer science portal for geeks
    p>
    <p lang="fr" class="lang-info">
        A computer science portal for geeks
    p>
    <p lang="es" class="lang-info">
        A computer science portal for geeks
    p>
body>
html>

Important Points About HTML Attributes

1. Always Use Lowercase Attributes:

• You can use either uppercase or lowercase letters for defining attributes.
• For example, both alt and ALT in an  tag are valid. However, it is recommended to use lowercase attributes as per W3C guidelines for consistency and better readability.

2. Always Quote Attribute Values:

• The HTML standard does not require quotes around attribute values in certain situations.
• However, W3C recommends always using quotes for attribute values, and quotes are mandatory for stricter document types like XHTML.
• Using quotes helps avoid errors, especially when the attribute value contains spaces or special characters.

3. Declare Quote as an Attribute Value:

• You can use either single (') or double (") quotes for attribute values in HTML, but it is essential to be consistent throughout your document.
• If the attribute value contains a double quote, then use single quotes to enclose it, and vice versa.For simplicity, it is a good practice to consistently use double quotes, as it aligns with the convention used in many HTML examples and tutorials.

In this example, the attribute value itself contains double quotes ("username"), so the entire value is enclosed within single quotes to avoid confusion.

4. Boolean Attributes Should Be Written Without Values:

• Boolean attributes do not require a value. If the attribute is present, it is considered true.
• For example, the checked attribute of an  element is correctly written as:

Example:

Writing checked="checked" also works, but it is redundant. Simply including the attribute is enough to represent a true state.

5. Proper Attribute Order for Readability:

• Although HTML does not enforce an order for attributes, following a consistent order improves readability and maintainability.
• It is common practice to order attributes like this: id, class, other global attributes, specific attributes, and finally, event attributes.

Submit

6. Avoid Deprecated Attributes:

• Certain HTML attributes, such as align, bgcolor, and border, are considered deprecated.
• It is better to use CSS for styling instead of outdated attributes.

This text is centered.

Instead of using the align attribute, use the style attribute or a CSS class to achieve the same effect.