When should I use a reference?
<p>Newbie here, I am reading some code, and I see sometimes the author used the reference in a function as </p>

<pre><code>funca (scalar&amp; a)
// Etc
</code></pre>

<p>Sometimes he just use</p>

<pre><code>funcb (scalar a)
// Etc
</code></pre>

<p>What's the difference? Is using a reference a good habit that I should have?</p>

<p>Thank you!</p>
