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POIn Scala, how can I get the max date from an array of maps where one of the keys in the map is "date"?
 

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  1. POIn Scala, how can I get the max date from an array of maps where one of the keys in the map is "date"?
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    <p>I have an array of maps and the maps and I would like to find the maximum date in the array of maps and I think I'm heading down a non-scala path because I'm not sure how to wire the pieces of this question together. </p> <p>Is there a better way of doing this? I'm concerned that I need to assume things like casting the value to a Date for comparison, but that is what's in the Map and the map includes other data types also (so Map[String, Object] is what I have)</p> <pre><code>val df = new SimpleDateFormat("yyyy-MM-dd") def omap = List(Map("date" -&gt; df.parse("2013-08-01")), Map("date" -&gt; df.parse("2013-02-01"), "otherkey" -&gt; "nothing special"), Map("date" -&gt; df.parse("2013-01-01"))) omap.max(new Ordering[Map[String, Object]] { def compare(x: Map[String, Object], y: Map[String, Object]) = x.get("date").get.asInstanceOf[Date] compareTo y.get("date").get.asInstanceOf[Date] }) </code></pre> <p>The code seems to work, but I feel like I'm missing a more scala like way of doing this.</p>
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    1. USAdamSpurgin
    1. USelemgee
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    1. COI'm not sure why @senia has a downvote, but `maxBy` seems like the right solution. I'd do `maxBy(_("date").asInstanceOf[Date])` but it's roughly the same thing. Stepping back a bit, having a map of `String` to `Object` feels bad. If you have structured objects that are guaranteed to always contain a field, use language features to say that or you'll run into bugs and aren't using your tools to their full potential. One solution might be to make a `case class` that has a `date` field of the right type, instead of a map with an untyped string mapping.
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      1. USMysterious Dan
 

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