September 2015
Intermediate to advanced
250 pages
6h 40m
English
Content preview from Pragmatic Scala
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Associative Maps
Suppose we want to attach the feed author’s name to feeds; we can store it as a key-value pair in a Map:
| | val feeds = Map("Andy Hunt" -> "blog.toolshed.com", |
| | "Dave Thomas" -> "pragdave.me", |
| | "NFJS" -> "nofluffjuststuff.com/blog") |
If we want to get a Map of feeds for folks whose name starts with “D,” we can use the filterKeys method:
| | val filterNameStartWithD = feeds filterKeys( _ startsWith "D" ) |
| | println(s"# of Filtered: ${filterNameStartWithD.size}") |
Here’s the result:
| | # of Filtered: 1 |
On the other hand, if we want to filter on the values, in addition to or instead of the keys, we can use the filter method. The function value we provide to filter receives a (key, value) tuple, and we can use it as ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.