title: Get only changed values from Reactive From of Angular
body: <p>I am working on an Angular-6 project. </p>
  
  <p>I have many forms with different structures. I want a generic method which returns only <strong>modified FromControls</strong> with <strong>modified values</strong>, doesn't matter what the Form structure is. </p>
  
  <p>I have thought of some ways to do that.</p>
  
  <p>One is to subscribe to <strong>valueChanges()</strong> method of every single <strong>FormControl</strong>. But the disadvantage is it messes up the code.</p>
  
  <p>The second way is that I can bind a method to event <strong>(change)</strong> for every <strong>FormControl</strong> and check if its value is changed or not. But again this doesn't seem to be the best way.</p>
  
  <p>Is there any way to do this in the appropriate manner?</p>