Extending Interfaces Like classes, interfaces can extend each other. This allows you to copy the members of one interface into another, which

instanceof type guards If you’ve read about typeof type guards and are familiar with the instanceof

Optional Parameters and Rest Parameters When comparing functions for compatibility, optional and required parameters are interchangeable. Extra

Import Importing is just about as easy as exporting from a module. Importing an exported declaration is done through using one of the import

Introduction Along with traditional OO hierarchies, another popular way of building up classes from reusable components is to build them by

Global augmentation You can also add declarations to the global scope from inside a module:

Function Types Interfaces are capable of describing the wide range of shapes that JavaScript objects can take. In addition to describing an

Performance Improvements The 1.1 compiler is typically around 4x faster than any previous release. See

gulp

Import a module for side-effects only Though not recommended practice, some modules set up some global state that can be used by other modules