title: Declaring a new variable inside Object
body: <p>I've been playing with JS and I'm trying to assign a new variable inside an object method but I keep getting hit with undefined in the console.</p>
  <p>This is the object I created:</p>
  <pre><code>const rodrigo = {
      firstName: 'Rodrigo',
      lastName: 'Pinto',
      job: 'Programmer',
      birthYEar: '1997',
      friends: ['Michael', 'Scott', 'Jim'],
      hasDriversLicense: true,
  
      calcAge: function () {
          this.age = 2021 - this.birthYEar;
          return this.age; //We don't actually need to return anything here actually, because we already said that age = calculation.
      }
  </code></pre>
  <p>But when I try to log rodrigo.age it returns undefined.
  Could someone walk me through this? I'm not understanding what I'm doing wrong.</p>