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    <p>The solution is to use <code>Option.map</code> and <code>Option.flatMap</code>:</p> <pre><code>First.flatMap(_.second.flatMap(_.third.map(_.numberOfSmth))) </code></pre> <p>Or the equivalent (see the <strong>update</strong> at the end of this answer):</p> <pre><code>First flatMap(_.second) flatMap(_.third) map(_.numberOfSmth) </code></pre> <p>This returns an <code>Option[Int]</code> (provided that <code>numberOfSmth</code> returns an <code>Int</code>). If any of the options in the call chain is <code>None</code>, the result will be <code>None</code>, otherwise it will be <code>Some(count)</code> where <code>count</code> is the value returned by <code>numberOfSmth</code>.</p> <p>Of course this can get ugly very fast. For this reason scala supports <em>for comprehensions</em> as a syntactic sugar. The above can be rewritten as:</p> <pre><code>for { first &lt;- First second &lt;- first .second third &lt;- second.third } third.numberOfSmth </code></pre> <p>Which is arguably nicer (especially if you are not yet used to seeing <code>map</code>/<code>flatMap</code> everywhere, as will certainly be the case after a while using scala), and generates the exact same code under the hood.</p> <p>For more background, you may check this other question: <a href="https://stackoverflow.com/questions/1052476/can-someone-explain-scalas-yield">What is Scala&#39;s yield?</a></p> <p><strong>UPDATE</strong>: Thanks to Ben James for pointing out that flatMap is associative. In other words <code>x flatMap(y flatMap z)))</code> is the same as <code>x flatMap y flatMap z</code>. While the latter is usually not shorter, it has the advantage of avoiding any nesting, which is easier to follow.</p> <p>Here is some illustration in the REPL (the 4 styles are equivalent, with the first two using flatMap nesting, the other two using flat chains of flatMap):</p> <pre><code>scala&gt; val l = Some(1,Some(2,Some(3,"aze"))) l: Some[(Int, Some[(Int, Some[(Int, String)])])] = Some((1,Some((2,Some((3,aze)))))) scala&gt; l.flatMap(_._2.flatMap(_._2.map(_._2))) res22: Option[String] = Some(aze) scala&gt; l flatMap(_._2 flatMap(_._2 map(_._2))) res23: Option[String] = Some(aze) scala&gt; l flatMap(_._2) flatMap(_._2) map(_._2) res24: Option[String] = Some(aze) scala&gt; l.flatMap(_._2).flatMap(_._2).map(_._2) res25: Option[String] = Some(aze) </code></pre>
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    1. POScala Option object inside another Option object
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    1. USRégis Jean-Gilles
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    1. POScala Option object inside another Option object
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    1. COYou don't need to use ugly nesting: because of the associativity of `flatMap`, `a flatMap (b flatMap c)` is equivalent to `a flatMap b flatMap c`
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      1. USBen James
    2. COThanks, you are very right. I usually nest them because this mimics the actual structure of what is mappped/flatMapped over (which **is** nested, as in this case). But it's true that it is more readable as a flat chain of `flatMap`.
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      1. USRégis Jean-Gilles
    3. CONote that not nesting flatMaps has the disadvantage of not being able to use a lambda parameter in nested lambda expressions, so although it works in this case I would not recommend it general. It's also slower and creates more function objects.
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      1. USJesper Nordenberg
 

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