class NamedValue<T> {

  private _value: T | undefined;

​

  constructor(private name: string) {}

​

  public setValue(value: T) {

    this._value = value;

  }

​

  public getValue(): T | undefined {

    return this._value;

  }

​

  public toString(): string {

    return `${this.name}: ${this._value}`;

  }

}

const value = new NamedValue<number>('myNumber');

​

value.setValue(10);

​

console.log(value.toString()); // myNumber: 10