title: How to concatenate two JSX fragment or variables or string and component (in Reactjs)?
body: <p>I know JSX can be very misleading because it looks like strings and it is not, thus the "string" term in the question, even if we are not really manipulating strings.</p>
  
  <p>Here is a code example (wrong, obviously):</p>
  
  <pre><code>let line = &lt;Line key={line.client_id} line={line}/&gt;;
  if(line.created_at) {
      return &lt;div className="date-line"&gt;&lt;strong&gt;{line.created_at}&lt;/strong&gt;&lt;/div&gt; + line;
  } else {
      return chat_line;
  }
  </code></pre>
  
  <p>I have a line, and I want to "concatenate" some divs in front of it under certain conditions. What would be the proper syntax?
  I've tried parenthesis, brackets, plus sign... None of them seem to work...</p>
  
  <p>thanks</p>