filteredArrayUsingPredicate does not exist in swift Array

Question

I have "UserDetails" struct objects in array..I want to filter the objects from array. But there is no option for "filteredArrayUsingPredicate" in Swift array.

My array creation

var arrayOfUsers:UserDetails[] = UserDetails[]() 

my userdetails code is

struct UserDetails{     var userName:String     var userID:String     var userAge:String     func userDescription()->String{         return "name " + userName + "age " + userID     } } 

my code to create objects

        for a in 1...1000{             var user:UserDetails = UserDetails(userName: "name", userID: String(a), userAge: "22")             arrayOfUsers.append(user)         } 

Now I want to filter arrayOfUsers which one has userID "1".

Answer 1

Swift arrays have a .filter method that takes a closure -- this will do it:

let filteredArray = arrayOfUsers.filter() { $0.userID == "1" } 

Closures can be simplified in a variety of ways. The full declaration of the closure would look more like this:

var filteredArray = arrayOfUsers.filter( { (user: UserDetails) -> Bool in         return user.userID == "1"     }) 

The difference between the two is that the first is using trailing closure syntax, shorthand argument names, type inference, and implicit return. You can read more about closures in Apple's Swift documentation.

Answer 2

you can also use NSPredicate

    var customerNameDict = ["firstName":"karthi","LastName":"alagu","MiddleName":"prabhu"];     var clientNameDict = ["firstName":"Selva","LastName":"kumar","MiddleName":"m"];     var employeeNameDict = ["firstName":"karthi","LastName":"prabhu","MiddleName":"kp"];     var attributeValue = "karthi";      var arrNames:Array = [customerNameDict,clientNameDict,employeeNameDict];       var namePredicate =         NSPredicate(format: "firstName like %@",attributeValue);      let filteredArray = arrNames.filter { namePredicate.evaluateWithObject($0) };     println("names = ,\(filteredArray)"); 

//struct filtering

struct myStruct {     var userid:String;     var details:String;     init() {         userid = "default value";         details = "default";     }  }; var f1 = myStruct(); f1.userid = "1"; f1.details = "Good boy";  var f2 = myStruct(); f2.userid = "2"; f2.details = "Bad boy"; var arrNames1:Array = [f1,f2]; let filteredArrayStruct =  arrNames1.filter( { (user: myStruct) -> Bool in     return user.userid == "1"     }) println("filter array count = \(filteredArrayStruct.count)"); for  filteredValues in filteredArrayStruct {        println("filteredArrayStruct = ,\(filteredValues.details)"); }