title: How to handle null value in string concatenation?
body: <p>I understand in PB that if there's a null value in variable concatenation then all the variable would return a null value. I'm trying to figure out if there's a way in handling the null values during the concatenation.</p>
  
  <p>See example below, ls_element3 returns a null value then definitely all the variables will return a  null value, what i want to happen is to return the values under ls_element1 and ls_element2. Anybody has an idea on how to handle the null values during string concatenation? </p>
  
  <pre><code>String ls_message, 
  ls_element1 = a, 
  ls_element2 = b, 
  ls_element3 = null
  
  ls_message = ls_element1 + ls_element2 + ls_element3
  </code></pre>