iOS facebookSDK get user full details

I guess this code should help you get the required details

Swift 2.x

let graphRequest : FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "me", parameters: nil)
    graphRequest.startWithCompletionHandler({ (connection, result, error) -> Void in

        if ((error) != nil)
        {
            // Process error
            print("Error: \(error)")
        }
        else
        {
            print("fetched user: \(result)")
            let userName : NSString = result.valueForKey("name") as! NSString
            print("User Name is: \(userName)")
            let userID : NSString = result.valueForKey("id") as! NSString
            print("User Email is: \(userID)")



        }
    })

In Swift 4.2 and Xcode 10.1

@IBAction func onClickFBSign(_ sender: UIButton) {

    if let accessToken = AccessToken.current {
        // User is logged in, use 'accessToken' here.
        print(accessToken.userId!)
        print(accessToken.appId)
        print(accessToken.authenticationToken)
        print(accessToken.grantedPermissions!)
        print(accessToken.expirationDate)
        print(accessToken.declinedPermissions!)

        let request = GraphRequest(graphPath: "me", parameters: ["fields":"id,email,name,first_name,last_name,picture.type(large)"], accessToken: AccessToken.current, httpMethod: .GET, apiVersion: FacebookCore.GraphAPIVersion.defaultVersion)
        request.start { (response, result) in
            switch result {
            case .success(let value):
                print(value.dictionaryValue!)
            case .failed(let error):
                print(error)
            }
        }

        let storyboard = self.storyboard?.instantiateViewController(withIdentifier: "SVC") as! SecondViewController
        self.present(storyboard, animated: true, completion: nil)
    } else {

        let loginManager=LoginManager()

        loginManager.logIn(readPermissions: [ReadPermission.publicProfile, .email, .userFriends, .userBirthday], viewController : self) { loginResult in
            switch loginResult {
            case .failed(let error):
                print(error)
            case .cancelled:
                print("User cancelled login")
            case .success(let grantedPermissions, let declinedPermissions, let accessToken):
                print("Logged in : \(grantedPermissions), \n \(declinedPermissions), \n \(accessToken.appId), \n \(accessToken.authenticationToken), \n \(accessToken.expirationDate), \n \(accessToken.userId!), \n \(accessToken.refreshDate), \n \(accessToken.grantedPermissions!)")

                let request = GraphRequest(graphPath: "me", parameters: ["fields": "id, email, name, first_name, last_name, picture.type(large)"], accessToken: AccessToken.current, httpMethod: .GET, apiVersion: FacebookCore.GraphAPIVersion.defaultVersion)
                request.start { (response, result) in
                    switch result {
                    case .success(let value):
                        print(value.dictionaryValue!)
                    case .failed(let error):
                        print(error)
                    }
                }

                let storyboard = self.storyboard?.instantiateViewController(withIdentifier: "SVC") as! SecondViewController
                self.navigationController?.pushViewController(storyboard, animated: true)

            }
        }
    }

}

https://developers.facebook.com/docs/graph-api/reference/user

As per the new Facebook SDK, you must have to pass the parameters with the FBSDKGraphRequest

if((FBSDKAccessToken.currentAccessToken()) != nil){
    FBSDKGraphRequest(graphPath: "me", parameters: ["fields": "id, name, first_name, last_name, email"]).startWithCompletionHandler({ (connection, result, error) -> Void in
        if (error == nil){
            println(result)
        }
    })
}

Documentations Link : https://developers.facebook.com/docs/facebook-login/permissions/v2.4

User object reference : https://developers.facebook.com/docs/graph-api/reference/user

With public profile you can get gender :

public_profile (Default)

Provides access to a subset of items that are part of a person's public profile. A person's public profile refers to the following properties on the user object by default:

id
name
first_name
last_name
age_range
link
gender
locale
timezone
updated_time
verified

Swift 4

An example in Swift 4 that also shows how to correctly parse out the individual fields from the result:

func fetchFacebookFields() {
    //do login with permissions for email and public profile
    FBSDKLoginManager().logIn(withReadPermissions: ["email","public_profile"], from: nil) {
        (result, error) -> Void in
        //if we have an error display it and abort
        if let error = error {
            log.error(error.localizedDescription)
            return
        }
        //make sure we have a result, otherwise abort
        guard let result = result else { return }
        //if cancelled nothing todo
        if result.isCancelled { return }
        else {
            //login successfull, now request the fields we like to have in this case first name and last name
            FBSDKGraphRequest(graphPath: "me", parameters: ["fields" : "first_name, last_name"]).start() {
                (connection, result, error) in
                //if we have an error display it and abort
                if let error = error {
                    log.error(error.localizedDescription)
                    return
                }
                //parse the fields out of the result
                if
                    let fields = result as? [String:Any],
                    let firstName = fields["first_name"] as? String,
                    let lastName = fields["last_name"] as? String
                {
                    log.debug("firstName -> \(firstName)")
                    log.debug("lastName -> \(lastName)")
                }
            }
        }
    }
}