Operator precedence determines how operators are parsed concerning each other. Operators with higher precedence become the operands of operators with lower precedence.

The do...while statement creates a loop that executes a specified statement as long as the test condition evaluates to true. The condition is evaluated after executing the statement, resulting in the specified statement executing at least once.

Classes are a template for creating objects. They encapsulate data with code to work on that data. Classes in JS are built on prototypes but also have some syntax and semantics that are unique to classes.

The decodeURI() function decodes a Uniform Resource Identifier (URI) previously created by encodeURI() or a similar routine.

Low-level languages like C, have manual memory management primitives such as malloc() and free(). In contrast, JavaScript automatically allocates memory when objects are created and frees it when they are not used anymore (garbage collection). This automaticity is a potential source of confusion: it can give developers the false impression that they don't need to worry about memory management.

The isNaN() function determines whether a value is NaN, first converting the value to a number if necessary. Because coercion inside the isNaN() function can be surprising, you may prefer to use Number.isNaN().

The equality (==) operator checks whether its two operands are equal, returning a Boolean result. Unlike the strict equality operator, it attempts to convert and compare operands that are of different types.

The RegExp object is used for matching text with a pattern.

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 <mask> SVG element defines a mask for compositing the current object into the background. A mask is used/referenced using the mask property and CSS mask-image property.