<div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"><div class="container">
<div class="line"><code class="jet keyword">package</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">multiplier</code>&nbsp;</div>
<div class="line">&nbsp;</div>
<div class="line"><code class="jet whitespace"></code><code class="jet jet-comment">//&nbsp;Return&nbsp;null&nbsp;if&nbsp;str&nbsp;does&nbsp;not&nbsp;hold&nbsp;a&nbsp;number</code>&nbsp;</div>
<div class="line"><code class="jet whitespace"></code><code class="jet keyword">fun</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">parseInt</code><code class="jet plain">(</code><code class="jet plain">str</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">:</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">String</code><code class="jet plain">)</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">:</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">Int</code><code class="jet plain">?</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">{</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet jet-comment">//&nbsp;...</code>&nbsp;</div>
<div class="line"><code class="jet whitespace"></code><code class="jet plain">}</code>&nbsp;</div>
<div class="line">&nbsp;</div>
<div class="line"><code class="jet whitespace"></code><code class="jet keyword">fun</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">main</code><code class="jet plain">(</code><code class="jet plain">args</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">:</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">Array</code><code class="jet plain">&lt;</code><code class="jet plain">String</code><code class="jet plain">&gt;</code><code class="jet plain">)</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">{</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet keyword">if</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">(</code><code class="jet plain">args</code><code class="jet plain">.</code><code class="jet plain">size</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">&lt;</code><code class="jet whitespace">&nbsp;</code><code class="jet number">2</code><code class="jet plain">)</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">{</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet plain">print</code><code class="jet plain">(</code><code class="jet string">&quot;</code><code class="jet string">No&nbsp;number&nbsp;supplied</code><code class="jet string">&quot;</code><code class="jet plain">)</code><code class="jet plain">;</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet plain">}</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet keyword">val</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">x</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">=</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">parseInt</code><code class="jet plain">(</code><code class="jet plain">args</code><code class="jet plain">[</code><code class="jet number">0</code><code class="jet plain">]</code><code class="jet plain">)</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet keyword">val</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">y</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">=</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">parseInt</code><code class="jet plain">(</code><code class="jet plain">args</code><code class="jet plain">[</code><code class="jet number">1</code><code class="jet plain">]</code><code class="jet plain">)</code>&nbsp;</div>
<div class="line">&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet jet-comment">//&nbsp;We&nbsp;cannot&nbsp;say&nbsp;'x&nbsp;*&nbsp;y'&nbsp;now&nbsp;because&nbsp;they&nbsp;may&nbsp;hold&nbsp;nulls</code>&nbsp;</div>
<div class="line">&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet keyword">if</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">(</code><code class="jet plain">x</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">!=</code><code class="jet whitespace">&nbsp;</code><code class="jet keyword">null</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">&amp;&amp;</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">y</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">!=</code><code class="jet whitespace">&nbsp;</code><code class="jet keyword">null</code><code class="jet plain">)</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">{</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet plain">print</code><code class="jet plain">(</code><code class="jet plain">x</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">*</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">y</code><code class="jet plain">)</code><code class="jet whitespace">&nbsp;</code><code class="jet jet-comment">//&nbsp;Now&nbsp;we&nbsp;can</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet plain">}</code>&nbsp;</div>
<div class="line">&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet jet-comment">//&nbsp;...</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet keyword">if</code><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet plain">(</code><code class="jet plain">x</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">==</code><code class="jet whitespace">&nbsp;</code><code class="jet keyword">null</code><code class="jet plain">)</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">{</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet plain">print</code><code class="jet plain">(</code><code class="jet string">&quot;</code><code class="jet string">Wrong&nbsp;number&nbsp;format&nbsp;in&nbsp;'</code><code class="jet escape">${</code><code class="jet plain">args</code><code class="jet plain">[</code><code class="jet number">0</code><code class="jet plain">]</code><code class="jet escape">}</code><code class="jet string">'</code><code class="jet string">&quot;</code><code class="jet plain">)</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet keyword">return</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet plain">}</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet keyword">if</code><code class="jet whitespace">&nbsp;&nbsp;</code><code class="jet plain">(</code><code class="jet plain">y</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">==</code><code class="jet whitespace">&nbsp;</code><code class="jet keyword">null</code><code class="jet plain">)</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">{</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet plain">print</code><code class="jet plain">(</code><code class="jet string">&quot;</code><code class="jet string">Wrong&nbsp;number&nbsp;format&nbsp;in&nbsp;'</code><code class="jet escape">${</code><code class="jet plain">args</code><code class="jet plain">[</code><code class="jet number">1</code><code class="jet plain">]</code><code class="jet escape">}</code><code class="jet string">'</code><code class="jet string">&quot;</code><code class="jet plain">)</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet keyword">return</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet plain">}</code>&nbsp;</div>
<div class="line"><code class="jet whitespace">&nbsp;&nbsp;&nbsp;&nbsp;</code><code class="jet plain">print</code><code class="jet plain">(</code><code class="jet plain">x</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">*</code><code class="jet whitespace">&nbsp;</code><code class="jet plain">y</code><code class="jet plain">)</code><code class="jet whitespace">&nbsp;</code><code class="jet jet-comment">//&nbsp;Now&nbsp;we&nbsp;know&nbsp;that&nbsp;x&nbsp;and&nbsp;y&nbsp;are&nbsp;not&nbsp;nulls</code>&nbsp;</div>
<div class="line"><code class="jet whitespace"></code><code class="jet plain">}</code></div></div></div></div>