Create type with two possible variants in Typescript

Question

Is there a way in Typescript to declare a variable which can be Int16Array or Uint16Array and nothing more?

Answer 1

TypeScript 1.4 has support for Type Unions, the notation is:

var arr: Int16Array|Uint16Array;

Common methods that both of these have will be available on arr. If you use instanceof or typeof checks on arr in conditional/branched code, it will infer the type of arr in those branches.

TypeScript 1.4. also has support for type aliases:

type My16Array = Int16Array | Uint16Array;

You can then use:

var arr: My16Array;