setAttribute vs. .attribute Notation in JavaScript: A Best-Practice Guide

When working with HTML elements in JavaScript, developers often face the choice between using the setAttribute() method and the dot (.) attribute notation to set attribute values. To determine the best practice, it's crucial to understand the subtle differences between these approaches.

setAttribute() vs. Dot Notation

The setAttribute() method is a standard JavaScript method used to set the value of an attribute on an HTML element. It takes two arguments: the attribute name and the desired value. For example:

myObj.setAttribute("className", "nameOfClass");
myObj.setAttribute("id", "someID");

Dot notation, on the other hand, provides a shorthand way to access and modify the properties of an object. When used with HTML elements, dot notation allows you to set attributes directly. For example:

myObj.className = "nameOfClass";
myObj.id = "someID";

Best-Practice Recommendations

According to Douglas Crockford's JavaScript: The Definitive Guide, the general best practice is to use dot notation for setting standard HTML attributes and setAttribute() for non-standard attributes.

• Standard Attributes: HTML elements have predefined properties that correspond to standard HTML attributes. For instance, className and id are both standard attributes, so they can be set directly using dot notation.
• Non-Standard Attributes: Custom or non-standard attributes, which are not part of the standard HTML specification, require the use of setAttribute(). For example, setting the frameborder attribute on an

Example

Consider the following code snippet:

const node = document.createElement('div');
node.className = 'test'; // Standard attribute
node.frameborder = '0'; // Non-standard attribute

// Non-standard attribute requires setAttribute()
node.setAttribute('frameborder', '0');

In this example, setting className using dot notation works because it is a standard attribute. However, frameborder is a non-standard attribute, so setAttribute() must be used to modify its value.

By following these best-practice guidelines, developers can ensure consistent and efficient attribute handling in their JavaScript code.