How to initialize empty dictionary in Typescript?

by

If you want to initialize an empty dictionary in Typescript, check out this complete tutorial. Here, I have explained how to initialize an empty dictionary in Typescript using various methods.

To initialize empty dictionary in Typescript, you can use the object literal syntax like let dictionary: { [key: string]: any } = {}; Here, the dictionary is a variable that will store our key-value pairs, where the keys are strings and the values can be of any type (any). The empty curly braces {} signify that the dictionary is currently empty.

Initialize an empty dictionary in Typescript

Now. let us check out a few methods to initialize an empty dictionary in Typescript.

1. Using Object Literal Syntax

The simplest way to initialize an empty dictionary in TypeScript is by using object literal syntax. Here is a complete code to initialize an empty dictionary in Typescript.

let dictionary: { [key: string]: any } = {};

Here, the dictionary is a variable that will store our key-value pairs, where the keys are strings, and the values can be of any type (any). The empty curly braces {} tell that the dictionary is currently empty.

2. Using the Record Utility Type

TypeScript offers a generic utility type called Record that can be used to create a dictionary type. Here’s how you can initialize an empty dictionary using Record in Typescript:

let dictionary: Record<string, any> = {};

3. Using an Interface

If you prefer to work with interfaces, or if your dictionary will have a consistent value type, you can define an interface for the dictionary and then initialize it in Typescript:

interface IDictionary {
    [key: string]: any;
}

let dictionary: IDictionary = {};

4. By Specifying Value Types

All the above methods have used any for the value type, which is not recommended for production code due to its lack of specificity. Let’s initialize an empty dictionary with a specified value type in Typescript:

let dictionary: { [key: string]: number } = {};

In this example, we’re declaring a dictionary that will have string keys and number values in Typescript.

5. Using the Map Object

TypeScript also supports the Map object, which is a collection of keyed data items, just like an Object but with some differences. Here’s how you can initialize a Map:

let dictionary = new Map<string, any>();

This is how to initialize an empty dictionary in Typescript using the Map object.

Conclusion

I hope now you have an idea of how to initialize an empty dictionary in Typescript using the below methods:

  1. Using Object Literal Syntax
  2. Using the Record Utility Type
  3. Using an Interface
  4. By Specifying Value Types
  5. Using the Map Object

You may also like:

>