How do i add objects into an array from a Class in Swift?-CodePudding

This is my Friend class:

class Friend {
    var firstName: String = ""
    var lastName: String = ""
    var age: Int = 0
    var description:String = ""

    init(firstname: String, lastname: String, age: Int) {
        self.firstName = firstname
        self.lastName = lastname
        self.age = age
    }
}

This is where i'm supposed to declare and instantiate 5 Friend objects in the viewDidLoad function and to add them into 'friendList' array.

import UIKit

class ViewController: UIViewController {

    var friendsList: [Friend] = []

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.

        friendsList.append("John", "Doe", 20)
    }
}

Swift tells me that "No exact matches in call to instance method 'append'" on the "friendsList.append" line.

CodePudding user response：

you can use like Below if you are creating all friends Initially

 let friends = [Friend(firstname: "John", lastname: "Doe", age: 20),Friend(firstname: "doe", lastname: "John", age: 21)]
    
    for friend in friends{
        friendsList.append(friend)
    } 
//////////////////////////////////////
 (or) you can directly declare value for your global variable  

friendsList = [Friend(firstname: "John", lastname: "Doe", age: 20),Friend(firstname: "doe", lastname: "John", age: 21)]
///////////////////////////////////////////

(or) assign local variable value to your global variable
friendsList = friends

or if you adding One by One,You have to create object first

  let friendOne = Friend(firstname: "John", lastname: "Doe", age: 20)
    friendsList.append(friendOne)

CodePudding user response：

The Array (Actually collection) function append takes a parameter of type <T> where T is a generic type, "the type of the elements in the array".

So if you have an array of Strings, you need to pass a String into append:

var strings = [String]()

strings.append("a string")

Since you have an array of Friend objects, you need to pass an instance of Friend to the append(_:) function. Does the expression inside the parentheses in your call to append evaluate to a friend object?

friendsList.append("John", "Doe", 20)

It doesn't. You'r passing a comma-separated list of properties. Presumably, those are the first name, last name, and age of a Friend, but the append() function doesn't know that.

You could write it as:

let aFriend = Friend(firstname: "John", lastname: "Doe", age: 20)
friendList.append(aFriend)

Or all in one line with:

friendList.append(Friend(firstname: "John", lastname: "Doe", age: 20))

Both of those variations would work.