Understanding getElementById

The getElementById method is a fundamental JavaScript function used to select a single HTML element by its id attribute. It returns the element object representing the element whose id property matches the specified string.

Example Usage:

Let's say you have the following HTML:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="root"></div>
    <script src="script.js"></script>
</body>
</html>

In your script.js file, you can use getElementById to select the div and manipulate it:

const root = document.getElementById("root");
const Heading = document.createElement("h1");
Heading.innerHTML = "Hello World";
root.appendChild(Heading);