What's the fastest way of concatenating strings in PHP?
<p>I want to combine two variables together:</p>

<p><code>$var1 = 'Welcome ';</code></p>

<p><code>$var2 = $_SESSION['UserName'];</code></p>

<p>Which of these will work faster? Code sample 1:</p>

<pre><code>$var3 = $var1.$var2;
</code></pre>

<p>Or code sample 2:</p>

<pre><code>$var3 = "$var1$var2";
</code></pre>
