How to use a function that was created inside the constructor?

Issue

I'm creating a function inside the constructor, and it needs to be done inside the constructor, I wanted a button to activate it externally, however I have no idea how to do this.

My TypeScript

  private functionActive;

  constructor(){

    this.functionActive = function hello(){

      console.log('Hello world');

    };

    }   

  }

  buttonActive(event){

    this.functionActive.hello();

  }

Solution

Two mistakes:

1. Define the function without the extra )

   constructor() {
      this.functionActive = function hello() {
         console.log("Hello world");
      };
   }
   

2. Invoke it using the reference of the function i.e. functionActive and not hello, as it is a function expression:

   buttonActive(event) {
      this.functionActive();
   }
   

Answered By - Nicholas Kurian