Store and recall button in calculator application (iPhone)
<p>I'm new in iPhone development. I made a calculator in which I need to put 2 more buttons:</p>

<ol>
<li><code>Store</code>: Stores the current value of the display into a memory location.</li>
<li><code>Recall</code>: Recalls the value in memory.</li>
</ol>

<p>But I don't know how.</p>
