单例

static-class.js

class Demo{
  private static instance: Demo;
  private constructor(public name: string) {}

  static getInstance() {
    if(!this.instance) {
      this.instance = new Demo('dell llw');
    }
    return this.instance;
  }
}

const demo1 = Demo.getInstance();
const demo2 = Demo.getInstance();
console.log(demo1.name);
console.log(demo2.name);