Thread 1: Fatal error: Index out of range In SwiftUI - ios

Question

i am trying to make a small Social Media app. the friends and friendrequest gets stored as User in different arrays. But when i want to loop the array it an shows which user send a request it first works but when i accept the user and he is remove from the Array i am getting this error "Thread 1: Fatal error: Index out of range" i know its because the loop wants to loop to a index which doesn't exist anymore but how do i fix it ?
struct FriendsView: View {
#EnvironmentObject var appUser: User
var body: some View {
List {
ForEach(0..<appUser.friendAnfrage.count) {
durchlauf in
SingleFriendView(user: appUser.friendAnfrage[durchlauf])
}
}
}
}
class User: ObservableObject{
#Published var username: String = ""
#Published var name: String = ""
var password: String = ""
#Published var email: String = ""
#Published var beschreibung: String = ""
#Published var profilBild: UIImage?
#Published var friends = [User]()
#Published var friendAnfrage = [User]()
#Published var anfrageGesendet = [User]()
#Published var feed = [SinglePostView]()
func addFriend(friend: User,appUser: User) {
friend.friendAnfrage.append(appUser)
appUser.anfrageGesendet.append(friend)
}
func newFriend(newFriend: User) {
friends.append(newFriend)
for i in 0..<friendAnfrage.count {
if friendAnfrage[i].username == newFriend.username {
friendAnfrage.remove(at: i)
}
}
}
func friendAnfrage(friend: User,appUser: User) {
appUser.friendAnfrage.append(friend)
}
func makePost(image: UIImage,appUser: User) {
feed.append(SinglePostView(bild: image, ersteller: appUser))
for i in 0..<friends.count {
friends[i].feed.append(SinglePostView(bild: image, ersteller: appUser))
}
}
}

Answer 1

ForEach with an index-based approach is dangerous in SwiftUI. Instead, make your model identifiable.
class User: ObservableObject, Identifiable {
var id = UUID()
//...
Then, change your loop:
ForEach(appUser.friendAnfrage) { item in
SingleFriendView(user: item)
}
Unrelated to this exact issue, but generally SwiftUI does better with using a struct for a model instead of a class. If a User in friends is updated with your current code, because it's a nested ObservableObject, your View will not get automatically updated.

Answer 2

User should be a struct and ForEach isn't a traditional loop, it's a View that must be supplied identifiable data, e.g.
struct FriendsView: View {
#EnvironmentObject var model: Model
var body: some View {
List {
ForEach($model.users) { $user in
SingleFriendView(user: $user)
}
}
}
}
struct User: Identifiable{
let id = UUID()
var username: String = ""
var friends: [UUID] = []
}
class Model: ObservableObject {
#Published var users: [User] = []
}