CODEWITHSUNDEEP
arraysswift
user9041624
user9041624

Reputation: 266

Swift 4 Array Find or First

I'm trying to perform a filter on an array of structs whereby if the element exists return the element, otherwise return the first element in the array. At the moment I have a func to do this, was wondering if there was a more efficient way. Predicate or Array extension?

For example, if this is my array of structures and method:

struct Person { 
   let name: String
   let age: Int
 }

 let items = [Person(name: "Fred", age: 12), 
              Person(name: "Bill", age: 14), 
              Person(name: "Jane", age: 15), 
              Person(name: "Mary", age: 12)]

 // Find the person based on name, if no match, return first item
 func filterOrFirst(with name: String? = "") -> Person?
 {
    if (items.contains(where: {$0.name == name}))
    {
        return items.first(where: {$0.name == name})
    }
    return items.first
 }

 print(filterOrFirst(with: "Bill"))   // prints Bill 
 print(filterOrFirst())               // prints Fred

Upvotes: 0

Views: 2932

Answers (2)

Chanchal Chauhan
Chanchal Chauhan

Reputation: 1560

You can do it like 

func filterOrFirst(with name: String? = "") -> Person? {
  if let item = items.first(where: {$0.name == name}) {
    return item
  }
  return items.first
}

So you need not to traverse complete array two times. You can use ternary operator here. But it increases compilation time.

Upvotes: 2

Abhirajsinh Thakore
Abhirajsinh Thakore

Reputation: 1822

You can get idea from this:

var arrData:[String] = ["Cat","Dog","Horse","Sheep"]

func respondTheValue(strSearch:String) -> String{

    let stringToSearch = strSearch

    if let index = arrData.index(of: stringToSearch){ //Check if data is present or not
        return arrData[index]
    }else{ // Data not present then return first
        return arrData.first!
    }
}

And use it Like:

 let responseStr = respondTheValue(strSearch: "Dog")
    print(responseStr) //Case True : Output -- Dog

 let responseStr1 = respondTheValue(strSearch: "Fish")
    print(responseStr1) //Case False : Output -- Cat

Hope this helps.

Upvotes: 0

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