Calculate the following expression. z = a ÷ (b + c) × (d2 - e) × f where a = 15, b = 3, c = 2, d = 4, e = 12, f = 4.
DOM is a programming API for HTML documents that represents the logical structure of documents. It provides access to all the elements in a document such as add or change HTML elements and attributes, remove existing HTML elements and attributes and etc. You have used one of the DOM methods which is getElementById method to access an element in an HTML document. In addition to getElementById, you can access elements by the element name (getElementsByTagName) and class name (getElementsByClassName).