Are accessors necessary in Typescript?

Question

I understand the importance of encapsulation in OOP, and accessors (getters/setters) provide this level of abstraction.

However, with Typescript I can substitute my property with accessors at a later date, with the same name, and rename my property to be prefixed with an underscore (therefore not causing a breaking change).

For example I could have:

class foo {

  name: string;

}

Later if I wish to add accessors to this property I could change to the following:

class foo {

  private _name: string;

  get name():boolean {
    return this._name;
  }

  set name(name: string) {
    this._name = name;
  }

}

Is this considered bad practice?

What is the purpose of the accessors in this context?

Such accessors have no purpose. They would have if they did something other than what a simple public field does (like computing some other property when the setter is called, for example). — JB Nizet, Jun 26 '18 at 18:49

artem · Accepted Answer · 2019-02-16T22:29:14.207

Accessors are an implementation detail. If you follow "program to the interface, not to the implementaion" rule, users of foo should only see

interface foo {
    name: string;
}

How exactly this interface is implemented does not matter. It could be a class with getters and setters, a class with public property, or even a plain object.

Whichever is best is determined by the constraints that particular implementation must obey. In most cases, accessors don't seem to be necessary, but could be convenient sometimes.

Are accessors necessary in Typescript?

1 Answers1