Is it possible to unwrap an optional/nullable value in TypeScript?

Question

I'm used to Swifts' optional values and see that TypeScript has something similar. For things like lazy initialisation of properties, it would be nice to have a private property that is nullable and a public getter that will initialise the value when requested.

class Test {
   private _bar: object:null = null;
   get bar(): object {
       if (_bar === null) {
           _bar = { };
       }
       return _bar;
   }
}

I know I could use undefined for this and remove the nullable type info from the private member, but I'm wondering if there is a way to do this without having to carry that null forever with the property. I'm going from a place where I want to handle null values to a boundary where I'd no longer wish for force anyone to deal with nullable values.

Answer 1

You can do this in TypeScript like so:

class Test {
  private _bar?: object;
  get bar(): object {
    if (this._bar === undefined) {
        this._bar = { };
    }
    return this._bar;
  }
}

Typically using undefined instead of null is more idiomatic in TypeScript.