title: How do I access an ngOnChanges field?
body: <p>My HTML looks something like this:</p>
  
  <pre><code>&lt;input type="number" class="form-control" id="khatianNumber" required [(ngModel)]="big.khatianNumberP1" name="khatianNumber" #khatianNumber="ngModel"&gt;
  
  &lt;p id="parapart" align="center"&gt;/&lt;/p&gt;
  
  &lt;input type="number" class="form-control" id="khatianNumber2" required [(ngModel)]="big.khatianNumberP2" name="khatianNumber2" #khatianNumber1="ngModel"&gt;
  </code></pre>
  
  <p>And my Angular looks something like this,</p>
  
  <pre><code>export class RegistrationComponent implements OnInit,OnChanges {
  isRequesting = false;
  steps = [];
  model = {
    khatianNumber: '',
  };
  
  big = {
    khatianNumberP1: '',
    khatianNumberP2: '',
  }
  ngOnChanges(changes: SimpleChanges){
      if (changes['big.plotNumberP1']){
          alert("hi");
      }
  }
  }
  </code></pre>
  
  <p>I've never used angular like this, I usually had to use scopes and controllers. </p>
  
  <p>Can someone tell me what am I doing wrong? Is there something wrong with my HTML or am I using the models wrong? I am new to Angular and would greatly appreciate if someone could clear this doubt!</p>