Default parameters swift
<p>For my default parameters should I write</p>

<pre><code>func myFunc(optionA: Int? = 0)
</code></pre>

<p>or</p>

<pre><code>func myFunc(optionA: Int! = 0)
</code></pre>

<p>Which is more advisable and/or more importantly which is used more in production? What happens if I use <code>Int!</code> instead of <code>Int?</code>? Can I still pass either an <code>Int</code>, <code>nil</code>, or no parameter whilst not having to unwrap the parameter when accessed? Is doing so considered lazy programming and may present potential memory insecurities?</p>