Optional Chaining Nullish Coalescing Assertion Functions Better Support for never -Returning Functions (More) Recursive Type Aliases --declaration and --allowJs The useDefi...

Control Flow Analysis of Aliased Conditions and Discriminants Symbol and Template String Pattern Index Signatures Defaulting to the unknown Type in Catch Variables (--useUnknown...

About this Handbook How is this Handbook Structured Non-Goals Get Started About this Handbook Over 20 years after its introduction to the programming community, JavaScript is...

Using TypeScript Using TypeScript ℹ️ This section has been moved to Using TypeScript Chapter .

Using TypeScript Using TypeScript In this chapter we will discuss: Overview of TypeScript in Deno Configuring TypeScript in Deno Types and Type Declarations Migrating to/fr...

Using TypeScript Using TypeScript In this chapter we will discuss: Overview of TypeScript in Deno Configuring TypeScript in Deno Types and Type Declarations Migrating to/fr...

Union types Overview Stricter Generics Better Type Inference let declarations const declarations Template strings Type Guards Type Aliases const enum (completely inlined e...

JSX support New .tsx file extension and as operator Using React Using other JSX framworks Output generation Intersection types Example Local type declarations Class express...

Type parameters as constraints Example Control flow analysis errors Unreachable code Example Unused labels Example Implicit returns Example Case clause fall-throughs Examp...

Generators and Iteration for ES5/ES3 Iterators Generators New —downlevelIteration Async Iteration Async iterators Async Generators The for-await-of Statement Caveats Gener...