Reactive Programming in iOS with Combine

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You've learned all about filtering operators so now it's time for a challenge. For this challenge, create a publisher that emits a collection of numbers from one to one hundred. Use filtering operators to skip the first 50 values emitted by the publisher, take the next 20 values from the publisher, only take even numbers. Pause the video, try coming up with the solution, and when you're ready, resume the video and I'll walk you through my solution. (upbeat music) Did you get the right sequence of numbers? Let's look at a solution. First making the publisher can be done just like the other examples in this part of the course using the collections built in publisher. To ignore the first 50 values from the publisher, you use drop first. Use the prefix operator to grab the next 20 values and be done. Next filter out the incoming values and accept only the ones that are even or divisible by two. Finally add the usual sync and store calls at the end. Run the playground and check the expected values. 52 through 70, just the even numbers. If you got this, great job.