如何将字符串或空值分配给变量 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.

Answer 1

You can check this one

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

const a: Nullable<MyValue> = null

Answer 2

Just declare a custom type

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

let name: names = null;