The export declaration is used to export values from a JavaScript module. Exported values can then be imported into other programs with the import declaration or dynamic import. The value of an imported binding is subject to change in the module that exports it — when a module updates the value of a binding that it exports, the update will be visible in its imported value.

The extends keyword is used in class declarations or class expressions to create a class that is a child of another class.

A mutable memory location.

A mutual exclusion primitive useful for protecting shared data

The mode attribute defines the blending mode on the <feBlend> filter primitive.

Function pointers, like `fn(usize) -> bool`.

the preserveAlpha attribute indicates how a <feConvolveMatrix> element handles alpha transparency.

Below, you'll find a list of errors which are thrown by JavaScript. These errors can be a helpful debugging aid, but the reported problem isn't always immediately clear. The pages below will provide additional details about these errors. Each error is an object based upon the Error object, and has a name and a message.

Utilities for the slice primitive type.

The new operator lets developers create an instance of a user-defined object type or of one of the built-in object types that has a constructor function.