title: Calling a method only when another is finished using Angular 6
body: <p>I have to execute 2 methods during a ngOnInit(), but the method2() must be executed only when the method1() is completely finished. I'm not doing HTTP requests, both methods belong to the same component. </p>
  
  <pre><code>  ngOnInit() {
      this.method1();
      this.method2(); //need to be executed only when method1() is finished
    }
  
    method1() {
      //do something
    }
  
    method2() {
      //do something but need to be started only when method1 is finished
    }
  </code></pre>
  
  <p>What is the best solution to this problem?</p>