This chapter discusses JavaScript's basic grammar, variable declarations, data types and literals.

This chapter introduces collections of data which are indexed by a key; Map and Set objects contain elements which are iterable in the order of insertion.

The AsyncGeneratorFunction object provides methods for async generator functions. In JavaScript, every async generator function is actually an AsyncGeneratorFunction object.

The decodeURIComponent() function decodes a Uniform Resource Identifier (URI) component previously created by encodeURIComponent() or by a similar routine.

The globalThis global property contains the global this value, which is usually akin to the global object.

The <ellipse> element is an SVG basic shape, used to create ellipses based on a center coordinate, and both their x and y radius.

The NaN global property is a value representing Not-A-Number.

There are several ways to color shapes (including specifying attributes on the object) using inline CSS, an embedded CSS section, or an external CSS file. Most SVG you'll find around the web use inline CSS, but there are advantages and disadvantages associated with each type.

The Proxy and Reflect objects allow you to intercept and define custom behavior for fundamental language operations (e.g. property lookup, assignment, enumeration, function invocation, etc.). With the help of these two objects you are able to program at the meta level of JavaScript.

The <feFuncR> SVG filter primitive defines the transfer function for the red component of the input graphic of its parent <feComponentTransfer> element.