How to initialize an object in TypeScript

If you don't want to change your definition from interface to class, you could also do:

let category = <Category>{ };

Otherwise, you could follow other answers and change your Category to be a class.

edit: as per ruffin's comment below, if the interface is

export interface ITiered { one: { two: { three: function (x) {...} } } } 

and you try let x = {} as ITiered, then you'll have an error when you call something like x.one.two.three()

There are a number of ways to solve this problem, depending on your desired result.

Way 1: Convert your interface to a class

export class Category {
  name: string;
  description: string;
}
const category: Category = new Category();

Way 2: Extend your interface as a class

export class CategoryObject implements Category {
}
const category: Category = new CategoryObject();

Way 3: Fully specify your object, matching the interface

const category: Category = {
  name: 'My Category',
  description: 'My Description',
};

Way 4: Make the properties optional

export interface Category {
  name?: string;
  description?: string;
}

const category: Category = {};

Way 5: Change your variable's type to use Partial<T>

export interface Category {
  name: string;
  description: string;
}

const category: Partial<Category> = {};