派生类是否更新其父类属性？

Question

I have several classes that are derived classes from a parent, they all update some values and I don't know if they have their own version of these values or they are actually updating the parent's properties as the app is navigated and different classes are being used, I suspect it's the latter.

It's the sideContent that I'm looking at, and any other property for that matter.

The parent:

export abstract class EngagementGraphNode {

  public sideContent: IEngagementSideContent;

  constructor(json?: IEngagementGraphNode) {
    if (json) {
      this.id = json.id;
      this.name = json.name;
    }
  }

Example of a child component:

export class EngagementProductGroup extends EngagementGraphNode {
  constructor() {
    super();
    this.placeholder = this.getIcon('more');
    this.icon = true;
    this.type = EngagementType.ProductGroup;
  }

  setProperties(json: IEngagementGraphNode, color: string): void {
    this.id = json.id;

      this.sideContent = {
        overview: { isLoading: true, title: 'Overview', id: 0 },
        members: { isLoading: false, title: 'Engaged Individuals', id: 1, individuals: this.individuals }
      }
    }

If this is the case, then I'm guessing at the point that the website is looking at that particular bit of code then that is updating the parent class as it goes along?

Thanks very much if you can help!

Answer 1

Every object has its own set of properties (instance variables) depending on how the property is declared.

If the parent property was declared with the static keyword (just like the public access modifier), then modifying the parent property from any of the children object would modify that value among all children objects (since it is being shared).

Since, they are not static in your case, each children has their own copy of the parent variable, which are safe from change when any of the children change their parent's variable.