title: I want to get the sum of three numbers without using + or * symbols
body: <p>I don't want use any + or * in my function, so I put &quot;var sum1 = a+b&quot; as a global variable
  then I put it in &quot;var sumAB&quot; to add to it the argument &quot;c&quot;.
  but I don't know what it is not working?</p>
  <p>hint:- I don't want to make var sum1 = a+b+c.</p>
  <pre><code>var sum1 = a+b //global variable
  
  function sumAndMultiply (a, b, c){
  
      var sumAndMulArray = [];
      var sumAb = (sum1, c)[0];
      var finalSum = (sumAb)[0];
      return sumAndMulArray[0] = finalSum
      console.log(sumAndMultiply); 
  }
  SumAndMultiply(4,7,5);
  </code></pre>