The instanceof operator tests to see if the prototype property of a constructor appears anywhere in the prototype chain of an object. The return value is a boolean value. Its behavior can be customized with Symbol.hasInstance.

A block statement is used to group zero or more statements. The block is delimited by a pair of braces ("curly braces") and contains a list of zero or more statements and declarations.

The BigUint64Array typed array represents an array of 64-bit unsigned integers in the platform byte order. If control over byte order is needed, use DataView instead. The contents are initialized to 0n unless initialization data is explicitly provided. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).

The const declaration declares block-scoped local variables. The value of a constant can't be changed through reassignment using the assignment operator, but if a constant is an object, its properties can be added, updated, or removed.

The comma (,) operator evaluates each of its operands (from left to right) and returns the value of the last operand. This is commonly used to provide multiple updaters to a for loop's afterthought.

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

The maskUnits attribute indicates which coordinate system to use for the geometry properties of the <mask> element.

The href attribute defines a link to a resource as a reference URL. The exact meaning of that link depends on the context of each element using it.

The class declaration creates a binding of a new class to a given name.

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