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.

Boolean values can be one of two values: true or false, representing the truth value of a logical proposition.

The switch statement evaluates an expression, matching the expression's value against a series of case clauses, and executes statements after the first case clause with a matching value, until a break statement is encountered. The default clause of a switch statement will be jumped to if no case matches the expression's value.

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.

The fill attribute has two different meanings. For shapes and text it's a presentation attribute that defines the color (or any SVG paint servers like gradients or patterns) used to paint the element; for animation it defines the final state of the animation.

The JavaScript exception "invalid property name in regular expression" or "invalid class property name in regular expression" occurs when the \p and \P Unicode character class escapes are not followed by a valid Unicode property name and/or value.

The intercept attribute defines the intercept of the linear function of color component transfers when the type attribute is set to linear.

The encodeURIComponent() function encodes a URI by replacing each instance of certain characters by one, two, three, or four escape sequences representing the UTF-8 encoding of the character (will only be four escape sequences for characters composed of two surrogate characters). Compared to encodeURI(), this function encodes more characters, including those that are part of the URI syntax.

The <animate> SVG element provides a way to animate an attribute of an element over time.

The async function* keywords can be used to define an async generator function inside an expression.