How can I write down a shortened if condition?

Question

Does anyone have an idea how to write the following code in a shortened form?

if self.atPoint(locationUser) == blueMarkArray[0] || self.atPoint(locationUser) == blueMarkArray[1] || self.atPoint(locationUser) == blueMarkArray[2] || self.atPoint(locationUser) == blueMarkArray[3] || self.atPoint(locationUser) == blueMarkArray[4] || self.atPoint(locationUser) == blueMarkArray[5] || self.atPoint(locationUser) == blueMarkArray[6]{

            print("its here")
        }

Furthermore, I don't want to commit myself to a fixed number of elements in the blueMarkArray array. It should be as variable as possible, because for example it can contain 4 elements, but also 12 elements.

For each answer I am very grateful.

EDIT:

How can you access the found element if I want to write the following: someNode.position = elementOfMarkArray.position

This is probably not a duplicate as I don't think you want to be testing if a point is in the list in that manner, due to floating point precision issues. You probably want to test if the point is *near* one of these points by calculating their distance. — trojanfoe, Feb 11 '19 at 10:28
Your added question is answered here: https://stackoverflow.com/a/24069331. — Martin R, Feb 11 '19 at 10:32
@MartinR I believe you are wrong marking this question as just another *find-in-list* issue. Please vote to re-open. — trojanfoe, Feb 11 '19 at 10:34
@trojanfoe: As I understand it, OP asks how to shorten the comparison against multiple array elements, or how to find its position in an array. That has been asked and answered before. – It *might* be better to find the “nearest” array element, but that is not what is asked here. — Martin R, Feb 11 '19 at 10:37
@MartinR Agreed the OP has not asked the question correctly; as well as being unaware of the nuisances of collection classes etc, they appear to lack understanding of 2D graphics. — trojanfoe, Feb 11 '19 at 10:38
@trojanfoe: Haven't seen you here for a while – welcome back! — Martin R, Feb 11 '19 at 10:39

mag_zbc · Accepted Answer · 2019-02-11T10:29:53.810

3

Use array's contains method

if (blueMarkArray.contains(self.atPoint(locationUser))) {
   //
}

or, if you need to check only up to index 6 like in your example, use

if (blueMarkArray[0...6].contains(self.atPoint(locationUser))) {
   //
}

if you want to get the index of the element, you can use firstIndex of lastIndex methods

if let index = blueMarkArray.firstIndex(of: self.atPoint(locationUser)) {
   //
}

edited Feb 11 '19 at 10:29

answered Feb 11 '19 at 10:17

mag_zbc

6,801
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It works, but how can you access the found element if I want to write the following: `someNode.position = elementOfMarkArray.position` – TimKrs Feb 11 '19 at 10:24
See updated answer – mag_zbc Feb 11 '19 at 10:27
Your first and second example are the same, the second doesn't actually check only up to index 6. There's also no need to use parentheses for the condition of an `if` statement in Swift, unlike in Objective-C (and the common pattern is not to use them). – Dávid Pásztor Feb 11 '19 at 10:29
@DávidPásztor an error during edit, now corrected – mag_zbc Feb 11 '19 at 10:30
Unfortunately, I still don't quite understand how to use `index`. Unfortunately it doesn't work that way: `if let index = blueMarkArray.firstIndex(of: self.atPoint(locationUser) as! SKSpriteNode) { someNode.position = index.position }` – TimKrs Feb 11 '19 at 10:35
I got it and it works. Thanks a lot – TimKrs Feb 11 '19 at 10:45

Dávid Pásztor · Answer 2 · 2019-02-11T10:38:52.183

You should simply use the contains method of Array, which will return true if any of the elements of the array equals self.atPoint(locationUser).

if blueMarkArray.contains(self.atPoint(locationUser)) {
    print("it's here")
}

If you also need to access the element that matches the object/value you are looking for, you can use first(where:) or firstIndex(of:).

if let location = blueMarkArray.first(where: {$0 == self.atPoint(locationUser)}) {
    someNode.position = location.position
}

or

if let locationIndex = blueMarkArray.firstIndex(of: self.atPoint(locationUser)) {
   let location = blueMarkArray[locationIndex]
   someNode.position = location.position
}

score 1 · Answer 3 · answered Feb 11 '19 at 10:18

1

You can use the array's method contains:

if blueMarkArray.contains(self.atPoint(locationUser)) {
    print("its here")
}

answered Feb 11 '19 at 10:18

Jarvis The Avenger

2,750
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19
37

How can I write down a shortened if condition?

3 Answers3