demo.component.ts

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-demo',
  templateUrl: './demo.component.html',
  styleUrls: './demo.component.scss'
})

export class DemoComponent implements OnInit {
  message: string,
  constructor: () {}
  
  ngOnInit {
    this.message = "Hello"
  }
}