JavaScript: Set Element's Attribute Value

setAttribute method

The setAttribute is generic, works in both HTML and XML.

node.setAttribute(AttributeName, value)

• set a node/element's attribute.
• Return undefined.
• If the attribute does not exist, it will be created.

The node is a HTML/XML node.

AttributeName and value should be string.

const tt = document.getElementsByTagName("a")[0];
tt.setAttribute("href", "http://example.com");

As of 2012-04-26, this works in all major browsers.

Set {Id, Clas, Href, Width} Attributes by Properties

If working in HTML (not XML), you can use a property directly for standard HTML attributes.

element.class = value

set class value. (must be a string)

When working with the class attribute, there are more convenient methods. [see JavaScript: List/Add/Remove Class Attribute]

element.id = value

set id value. (must be a string)

LinkElement.href = value

set href value. (must be a string)

ImgElement.width = value

set width value. (must be a string)

This

x.href = "http://example.com";

is same as

x.setAttribute("href", "http://example.com");

When working with XML, such as SVG, you should use setAttribute, because it is more general. [see JavaScript: Get Element's Attribute Value]