Do you think IIT Guwahati certified course can help you in your career?
Introduction
Hello Ninja, I hope you are doing great. Do you know about Class and Id in HTML? If not, don't worry. We are here to enrich your knowledge and clear all your doubts.
This article will discuss classes and ID’s along with their differences. We will also discuss HTML attributes other than classes and ID’s. After that, we will analyze classes and ID’s with the help of their respective codes and outputs.
What is an Attribute?
Attributes are used to provide additional details about an HTML element. Each HTML element or tag can have attributes that define the behavior of that element. It includes metadata about the element such as its size and colour.
Some examples of attributes are:
The href Attribute
Here href stands for “Hypertext Reference”. The href Attribute is mainly used in anchor tags (<a>) to specify the URL of the link. When a user clicks on the link specified by the href attribute, the browser will navigate to that page.
For example:
<a href = “https://www.codingninjas.com”> </a>
The src Attribute
Here src stands for “Source”. The src Attribute is used in image tags (<img>) to specify the URL of external resources such as image, audio and video that should be displayed or played in the browser.
For example:
<img src = “codingninjas_logo.jpg”>
We can also pass height and width attributes in an img tag to specify the height and width of an image.
To specify the class for a specific HTML element, we use a “class” attribute. We use class to group some HTML elements to apply the same properties to all those elements.
It reduces the code length. We don’t need to individually apply the common properties to all the HTML elements. Classes are assigned to the HTML elements like div and span. We can assign multiple classes to each HTML element.
For example: <div class = “class_A class_B class_C”> </div>
This div tag contains three classes and we can access anything inside this div tag by any of these three classes.
Lets see an example to understand the working of the classes in HTML.
We have added a class attribute in <p> tag named “styling”. Inside the style tag, we are using some properties of CSS. We are changing the color of the text and its background color and also aligning the text to the center.
You can see that we have added a dot( . ) before “styling” to use some properties of the CSS. Classes in HTML are case-sensitive, so make sure you use the correct name and always use { } brackets with the class name to use the CSS properties.
What is an ID in HTML?
It is an attribute specifying an HTML element's unique Id. No more than one HTML element can have the same Id. In CSS, we can select elements by their Id but remember to add (#) symbol before the Id name. In javascript, we can access elements with a given Id using the getElementById() method. Some of the standard HTML tags which use Id as an attribute are <div>, <p>, <a>, <form>, <input>, and <button>.
For example: <div id = “id1”> </div>
Here the div tag has an Id attribute with the value “id1”.
Lets see an example to understand the working of an Id in HTML.
Code
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title> Code Studio </title>
<style>
#header-id {
background-color: black;
color: orange;
padding: 50px;
text-align: center;
}
</style>
</head>
<body>
<h1 id = "header-id">
This is some random text
</h1>
</body>
</html>
Output
We have added an id attribute in <h1> tag named “header-id”. We are changing the color of the text, background color, alignment, and padding inside the style tag. Note that we are adding the (#) symbol before the id-name. So make sure to add this symbol and always use {} brackets with the id-name to use the properties of CSS.
Difference Between Class and ID
Class
Id
Classes are used to group elements having similar functionalities.
IDs are used to uniquely identify a single element on the web page.
Multiple elements can have the same class.
No more than one element can have the same Id.
The specificity of classes are lower than IDs. Style applied to a class cannot override the style applied to an Id
The specificity of IDs are higher than classes. Style applied to an Id can override the style applied to a class.
Search engines give less weightage to the classes over IDs.
Search engines give more weightage to the IDs over classes.
Dot (.) is used before the class name to style an element with a class.
Hash (#) is used before the Id-name to style an element with a specific ID.
THe scope of a class is wider than an ID, and it can affect all the elements on the page with that class.
The scope of an Id is limited compared to a class, and it can only affect a single element with that specific ID.
.
Syntax:
.class-name {
// CSS properties
}
Syntax:
#id-name {
// CSS properties
}
Frequently Asked Questions
Can id and class be same in HTML?
No, both id and class attributes can't be the same in HTML. The id attribute is used to uniquely identify an element, while the class attribute can be used to apply styles or group elements with similar characteristics.
What is the difference between class and name in HTML?
In HTML, the class attribute is used to apply styles or group elements with similar characteristics, while the name attribute is primarily used with form elements to identify and reference them in scripts or when submitting form data.
How to write ID and class?
To assign an id to an HTML element, use the id attribute followed by a unique identifier. For example: <div id="myId">. To assign a class, use the class attribute followed by one or more class names separated by spaces. For example: <div class="myClass">.
Conclusion
In this article, you’ve learned about the differences between Class and ID in HTML. Understanding the differences between the class and id attributes in HTML is crucial for effective web development. While both serve to style and identify elements, the class attribute allows grouping and applying styles to multiple elements, whereas the id attribute uniquely identifies a single element.
7+ registered 
