title: Counting number of holes in a number
body: <p>I'm trying to figure out how to count the number of "holes" in a number. That is, where 8 has two holes and 0, 4, 6, 9 have one hole and the rest have none. </p>
  
  <p>For some reason I'm getting a return of undefined and I'm pulling my hair out over it. Am I missing something?</p>
  
  <pre><code>var numOfHoles = 0;
  
     for (i = 0; i &lt; num.length; i++) {
  
     if (num === 8) {
         numOfHoles += 2; 
        }
         else if (num === 0 || num === 4 || num === 6 || num === 9) {
             numOfHoles++;
      }
       else
          numOfHoles;
    }
      console.log(numOfHoles);
  }
  </code></pre>