Find instead of Filter Array in Swift

Question

I have an array of PFObjects. I'd like to search if the "Type" contains "Sushi". The filter alters the array. How can I preform this search without altering the array?

func startCheckOptions(objects: [AnyObject]) {     
  let filteredArray = objects.filter() {
      if let type = ($0 as PFObject)["Type"] as String {
          //if "type" contains "sushi", then do something instead of alter array
          return type.rangeOfString("Sushi") != nil
      } else {
          return false
      }
  }
}

Nate Cook · Accepted Answer · 2015-01-06 05:00:47Z

3

You can use the contains function:

func startCheckOptions(objects: [AnyObject]) -> Bool {     
    return contains(objects as [PFObject]) { (object) -> Bool in
        if let type = object["Type"] as? String {
            return type.rangeOfString("Sushi") != nil
        }
        else {
            return false
        }
    }
}

if startCheckOptions(objects) {
    println("yes")
}
else {
    println("no")
}

This has the advantage of not building a new array containing the matching objects and stopping on the first match.

In this case you'd be better off protecting the objects cast (or really handling one time somewhere else) by casting it to [PFObject] ASAP. Leaving AnyObject references floating around can only lead to confusion and heartache.

edited Jan 6, 2015 at 5:00

Nate Cook

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answered Jan 5, 2015 at 23:06

David Berry

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4 Comments

Onichan Over a year ago

Thanks for the answer. I forgot to mention objects is type [AnyObject] (updated code). The code above generates the error at contains. "Type AnyObject does not conform to protocol Equatable"

Onichan Over a year ago

thanks this code compiles without error. however, i don't quite understand how I can preform any action if "type" contains "sushi". For instance, I tried printing yes if true and no if false.

David Berry Over a year ago

Maybe this edit answers your question, if it doesn't, I'm not sure what your question is.

Onichan Over a year ago

yep, that's actually what I ended up doing, except all within the function (just added a second if statement for hasSushi). I was just wondering if there was a more efficient way because I will be checking multiple "Types"

tng · Accepted Answer · 2015-01-05 22:51:15Z

0

filter() does not alter an array, but it returns a new array. What you have above is correct. objects will be the original array, and filteredArray will be the new array consistent of objects where "type" is "sushi".

answered Jan 5, 2015 at 22:51

tng

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2 Comments

Onichan Over a year ago

Is there a more direct way to check if the original array "Type" contains "Sushi" without requiring a return value.

tng Over a year ago

You can use the contains() function.

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