Beginning Collection Views - Part 19: Section 2: | Ray Wenderlich

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In this short video you'll learn about a property which will to enable you to longpress on a collection view and move cells around.

This is a companion discussion topic for the original entry at https://www.raywenderlich.com/4448-beginning-collection-views/lessons/19
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Hi, Catie & Jessy!
Thank you for great course! (and for authors of original courses) )
A little question about DataSource.swift:

private func loadParksFromDisk() -> [Park] {
	sections.removeAll(keepingCapacity: false)

Why do you use .removeAll instead of assiging an empty array? Does this approach has any (theoretical) performance or stylistic advantages or just a matter of personal preferences?

Thank you in advance!

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Syntactically, removeAll makes better sense to me personally since you are clearing up an existing array and adding new elements to it. But functionally (and performance-wise) I believe both removeAll and assigning an empty array do about the same thing.

See the following Stack Overflow thread if you are interested in the nitty gritty details:

1 Like
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Hi catie & Jessy,
We can move single cell at a time which is really cool. Is it possible to move multiple cells at a time? Any possible approach.

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You should be able to move multiple cells at a time around using the new Drag & Drop API in iOS 11. Take a look at the following WWDC video to see the details:

https://developer.apple.com/videos/play/wwdc2017/223/

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Hi Catie & Jessy,
A little extra feature I am curious about:
How would you approach to move cells only within the sections?

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@catie Can you please help with this when you get a chance? Thank you - much appreciated! :]