Mastering TypeScript/

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Multiple Exports and Namespaces

Multiple Exports and Namespaces

Learn how to import multiple symbols from a module using named imports or the * as syntax for namespace attachment.

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Multiple exports

When working with external libraries—that is, libraries that have been published for general consumption—it is common practice for a published library to export all classes, functions, and interfaces from a single module file.

This means that we do not need to know how this library is structured or how complex the class hierarchy is internally; we simply import the entire library from one file.

As an example of this technique, suppose we have a file named modules/MultipleExports.ts, as follows:

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// This is a TypeScript code that exports two classes, MultipleClass1
// and MultipleClass2, using the 'export' keyword.
export class MultipleClass1 {}
export class MultipleClass2 {}
// It's worth noting that these classes are empty, meaning they don't have any properties
// or methods defined within them.
  • We export two classes from this module file, which are named MultipleClass1 and MultipleClass2.

We can then import both of these classes in our modules_main.ts file as follows:

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// Importing MultipleClass1 and MultipleClass2 from the "MultipleExports" module using
// destructuring syntax
import { MultipleClass1, MultipleClass2 }
 from "./modules/MultipleExports";
// Instantiating a new object of class MultipleClass1 and assigning it to the variable "mc1"
let mc1 = new MultipleClass1();
// Instantiating a new object of class MultipleClass2 and assigning it to the variable "mc2"
let mc2 = new MultipleClass2();
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