31. Aliases

Aliases in TypeScript

In TypeScript, aliases can be used to simplify or shorten access to types or namespaces. One common use case is when you want to import a specific part of a namespace and assign it a shorter or more convenient name, using the import statement. This is especially helpful when working with deeply nested namespaces.

Example with Aliases

In this example, we’ll create a Shapes namespace containing a nested Polygons namespace. We’ll then use an alias to simplify accessing classes from the Polygons namespace.

Code Example:

namespace Shapes {
  export namespace Polygons {
    export class Triangle {}
    export class Square {}
  }
}
 
// Create an alias for the Polygons namespace
import polygons = Shapes.Polygons;
 
// Now, you can use the alias to refer to the classes
let sq = new polygons.Square();  // Same as 'new Shapes.Polygons.Square()'

Explanation:

• Nested namespaces: Polygons is a nested namespace within Shapes.
• Alias: import polygons = Shapes.Polygons; creates an alias polygons for the Shapes.Polygons namespace.
• Usage: You can now use the alias polygons to access the Square class without needing to fully reference the nested namespace path (Shapes.Polygons.Square).

This reduces the need to repeatedly use the full namespace path and makes your code cleaner and more concise.