Simple web calculator: Adding properties to calculator class

calculator-properties-ts.diff

class Calculator extends HTMLElement {
+  #display: HTMLElement | null = null;

+  #buttons: HTMLButtonElement[] = [];

+  #query = '';

+  public get query(): string {
+      return this.#query;
+  }

+  public set query(value: string) {
+      this.#query = value;
+  }

  constructor() {
    super();
  }
}

customElements.define('ws-calculator', Calculator);