title: Which data properties need to change to trigger an update?
body: <p>I am practicing vue js. This is the vue.js code</p>
  <pre><code>new Vue({
   el: '#people',
   data: {
    var1: 0,
    var2: null,
    var3: 'Hello',
    var4: 'Yassss'
   },
   computed: {
    var5: function() {
    let var1 = 0;
    if(this.var2 != null){
      var1++;
    }
    console.log(this.var3);
    return var1;
   }
  }
  });
  </code></pre>
  <p>This is the html code</p>
  <pre><code>&lt;p&gt;{{ var5 }}&lt;/p&gt;
  </code></pre>
  <p>The thing I am trying to understand is which data properties would need to change to trigger an update to the page</p>
  <p>Currently it is giving out the following output:</p>
  <pre><code>{{ var5 }}
  </code></pre>
  <p>I tried changing all of them in different combinations but it doesn't seem to work.</p>