JavaScript Date objects represent a single moment in time in a platform-independent format. Date objects encapsulate an integral number that represents milliseconds since the midnight at the beginning of January 1, 1970, UTC (the epoch).

The SVG <style> element allows style sheets to be embedded directly within SVG content.

The toLocaleDateString() method of Date instances returns a string with a language-sensitive representation of the date portion of this date in the local timezone. In implementations with Intl.DateTimeFormat API support, this method simply calls Intl.DateTimeFormat.

The void operator evaluates the given expression and then returns undefined.

The <title> element provides an accessible, short-text description of any SVG container element or graphics element.

JavaScript is a prototype-based language — an object's behaviors are specified by its own properties and its prototype's properties. However, with the addition of classes, the creation of hierarchies of objects and the inheritance of properties and their values are much more in line with other object-oriented languages such as Java. In this section, we will demonstrate how objects can be created from classes.

The constructor method is a special method of a class for creating and initializing an object instance of that class.

Static initialization blocks are declared within a class. It contains statements to be evaluated during class initialization. This permits more flexible initialization logic than static properties, such as using try...catch or setting multiple fields from a single value. Initialization is performed in the context of the current class declaration, with access to private state, which allows the class to share information of its private properties with other classes or functions declared in the same scope (analogous to "friend" classes in C++).

The <desc> element provides an accessible, long-text description of any SVG container element or graphics element.