Using a Set
Suppose we’re writing an RSS feed reader and we want to frequently update the feeds, but we don’t care about the order. We can store the feed URLs in a Set. Assume we have the following feeds stored in two Sets:
| | val feeds1 = Set("blog.toolshed.com", "pragdave.me", "blog.agiledeveloper.com") |
| | val feeds2 = Set("blog.toolshed.com", "martinfowler.com/bliki") |
If we want to update only select feeds from feeds1, say the ones that have the word “blog,” we can get those feeds using the filter method:
| | val blogFeeds = feeds1 filter ( _ contains "blog" ) |
| | println(s"blog feeds: ${blogFeeds.mkString(", ")}") |
We’ll get this output:
| | blog feeds: blog.toolshed.com, blog.agiledeveloper.com |
The mkString method creates a string ...
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