How to assign either a string or null to a variable TypeScript

Question

I have a variable which either can take string or null, currently i am defining all the type values hardcoded as below

  let name : 'Ram' | 'Shyam' | 'Paul' | null = null;
  name = customer.name as 'Ram' | 'Shyam' | 'Paul' | null;

Here, the values are hardcoded, how can i make it generic so that it can intake anything old and new both.

Nghi Nguyen · Accepted Answer · 2020-08-25 06:10:42Z

8

You can check this one

type MyValue = "A" | "B" | "C"
type Nullable<T>  = T | null

const a: Nullable<MyValue> = null

answered Aug 25, 2020 at 6:10

Nghi Nguyen

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2 Comments

I like this Nullable approach, surprisingly I have never seen that before.

Thanks @Zer0 I'm happy to share it for everyone :)

Zer0 · Accepted Answer · 2020-08-25 06:09:19Z

4

Just declare a custom type

type names = 'Ram' | 'Shyam' | 'Paul' | null;

let name: names = null;

answered Aug 25, 2020 at 6:09

Zer0

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