title: php sum with add symbol as variable
body: <p>I have this variable</p>
  
  <pre><code>$option_value['price'] = 2
  $option_value['price_prefix'] = +
  $this-&gt;data['price2'] = 3
  </code></pre>
  
  <p>I have tried to make sum from it like this</p>
  
  <pre><code>$price = $option_value['price'].''.$option_value['price_prefix'].''.$this-&gt;data['price2'];
  echo $price 
  </code></pre>
  
  <p>but the result is 2. What I want is 5. </p>
  
  <p>Prease help</p>