Quite straight question on how to write clean code here. Assuming I have a property with a backing field:

get value(): string { return this._value; }
set value(v: string) { this._value = v; }
private _value?: string;

this code is invalid since _value is undefined by default. To I actually have to write

get value(): string | undefined { return this._value; }

each time? Is there no shorthand? Looks pretty creepy to me. If I now accept null values, too, I’d have to write

get value(): string | undefined | null { return this._value; }
set value(v: string | null) { this._value = v; }
private _value?: string | null;

every time. Nicer solution? Or is as it is?