JavaScript - createAttribute() method

revision:

Category : document

The Document.createAttribute() method creates a new attribute node, and returns it. The object created is a node implementing the Attr interface. The DOM does not enforce what sort of attributes can be added to a particular element in this manner.

Syntax : 

            document.createAttribute(name)

Parameters:

name : required; a string containing the name of the attribute to be created.

Examples: 

            const node = document.getElementById("div1");
            const a = document.createAttribute("my_attrib");
            a.value = "newVal";
            node.setAttributeNode(a);
            console.log(node.getAttribute("my_attrib")); // "newVal"

Practical examples

example: click "Add" to create a class attribute and add it to the first h4 element

The first h4 heading

The second h4 heading

The third h4 heading

code: 
                    <div>
                        <h4>The first h4 heading</h4>
                        <h4>The second h4 heading</h4>
                        <h4>The third h4 heading</h4>
                        <button onclick="addFunction()">Add</button>
                    </div>
                    <style>
                        .democlass {color: red;}
                    </style>
                    <script>
                        function addFunction() {
                            // Create a class attribute:
                            const att = document.createAttribute("class");
                            // Set a value of the class attribute
                            att.value = "democlass";
                            // Add the class attribute to the first h1;
                            document.getElementsByTagName("h4")[0].setAttributeNode(att);
                        }
                        
                    </script>

example: create a style attribute that adds a red color to the h4 element.

The fourth h4 heading

The fifth h4 heading

code: 
                    <div>
                        <h4>The fourth h4 heading</h4>
                        <h4>The fifth h4 heading</h4>
                    </div>
                    <script>
                        // Create a class attribute:
                        const att1 = document.createAttribute("style");
                        // Set the value of the class attribute
                        att1.value = "color:red";
                        // Add the class attribute to the first h1;
                        const h4 = document.getElementsByTagName("h4")[4];
                        h4.setAttributeNode(att1);

example: add a "href="www.lwitters.com" attribute to an anchor element.
Go to lwitters.com

Click "Add" to add a href attribute to the anchor above.

code: 
                    <div>
                        <a id="myAnchor2">Go to lwitters.com</a>
                        <p>Click "Add" to add a href attribute to the anchor above.</p>
                        <button onclick="goFunction()">Add</button>
                    </div>
                    <script>
                        function goFunction() {
                            // Create a href attribute:
                            const attr = document.createAttribute("href");
                            // Set the value of the href attribute:
                            attr.value = "https://www.lwitters.com";
                            // Add the href attribute to an element:
                            document.getElementById("myAnchor2").setAttributeNode(attr);
                            }
                    </script>