title: Return and "this". How can i do. JavaScript
body: <pre><code>const john = {
      firstName: &quot;Jhon&quot;,
      lastName: &quot;Smith&quot;,
      weight: 92 ,
      height: 1.95 ,
  
      calcBmi: function() {
            this.bmi = this.weight / ( this.height * 2 );
          return this.bmi;
       }
    }
  console.log(john.bmi)
  </code></pre>
  <p>Output in console its &quot;undefined&quot; can someone explain what i need to do? Its work if i write &quot;console.log(john.calcBmi())&quot; but i want to create a new variable in this object and use after that multiple time</p>