在对象数组中查找对象 Swift

Question

I have a custom object array of type LeaderboardUser() . This object contains a string variable of "uid", "email".

I am trying to make a statement to recognize if the uid given matches the uid of the LeaderBoard

if self.allFriends.contains() {
    // Remove user
    Database.database().reference().child("Users").child(Auth.auth().currentUser!.uid).child("Friends").child(self.uid).removeValue()
} else {
    // Add user
    let key = Database.database().reference().child("Users").childByAutoId().key
    let friends = ["uid" : "\(self.uid)"] as [String : Any]
    let totalList = ["\(key!)" : friends]
    Database.database().reference().child("Users").child(Auth.auth().currentUser!.uid).child("Friends").updateChildValues(totalList)
}

Is there any way that I can search the UID parameter? I tried a contains() bool, but I don't know what and how how that works.

Answer 1

You just need to use contains(where: method here.

if self.allFriends.contains(where: { $0.uid == uidOfLeaderBoard }) {
    //...
}

Answer 2

Param of contents func is a closure that takes an element of the sequence as its argument and returns a Boolean value that indicates whether the passed element represents a match

@inlinable public func contains(where predicate: (Element) throws -> Bool) rethrows -> Bool

you can using it like:

        if allFriends.contains(where: { (leaderboardUser) -> Bool in
            return leaderboardUser.uid == idYouWantToFind
        }) {

        }

or with sort version:

        if allFriends.contains(where: { $0.uid == idYouWantToFind}) {

        }

and if you make your LeaderboardUser comfort to Equatable protocol, you can use like this:

class LeaderboardUser: Equatable {
    var uid: String = ""
    var email: String = ""

    static func == (lhs: LeaderboardUser, rhs: LeaderboardUser) -> Bool {
        return lhs.uid == rhs.uid
    }
}

        if allFriends.contains(userWantToFind) {

        }