title: Function inside array of objects not processed and return as string JS
body: <p>I have an array of objects, at this moment there is just one object inside. In this object i have a function that elaborate some properties of the same object. I print, with a loop, the components, but the function is not processed and the string is returned. How can i have the result?</p>
  <pre><code>let arrMaterie = [
      {
          name: &quot;...&quot;,
          a: 4,
          b: 75,
          functionTest: function test() {
              return this.a+this.b;
          }
      }
  ];
  
  for (let i in arrMaterie) {
      for (let j in arrMaterie[i]) {
          test.innerHTML += arrMaterie[i][j];
      }
  }
  </code></pre>
  <p>OUTPUT ...475function test() { return this.a - this.b }
  and not ...-4-75-<strong>79</strong></p>