Swift filter array of strings

Question

I\'ve had troubles filtering array of keywords (strings) in swift ,My code:

self.filteredKeywords=filter(keywords.allValues, {(keyword:NSString) ->                    


        

Answer 1

There is both a problem with GoZoner's answer for certain data types and also a slightly better way to do this. The following examples can show this:

let animalArray: NSMutableArray = ["Dog","Cat","Otter","Deer","Rabbit"]
let filteredAnimals = animalArray.filter { $0.rangeOfString("er") != nil }
print("filteredAnimals:", filteredAnimals)

filteredAnimals: [Dog, Cat, Otter, Deer, Rabbit]

Likely not the set you expected!

However this works fine this way if we don't type animalArray as an NSMutableArray:

let animalArray = ["Dog","Cat","Otter","Deer","Rabbit"]
let filteredAnimals = animalArray.filter { $0.rangeOfString("er") != nil }
print("filteredAnimals:", filteredAnimals)

filteredAnimals: [Otter, Deer]

However I'd recommend using $0.contains() instead of $0.rangeOfString() != nil because it functions in both circumstances and slightly enhances the readability of the code:

let animalArray: NSMutableArray = ["Dog","Cat","Otter","Deer","Rabbit"]
let filteredAnimals = animalArray.filter { $0.contains("er") }
print("filteredAnimals:", filteredAnimals)

filteredAnimals: [Otter, Deer]