Doubt session 28/9/24

listManipulation.dart

import 'dart:io';
void main() {
  List<int> listOfNumbers = [];

  late String inputFromUser;
  while (true) {
    print("Enter the operation to do: ");
    print("1. Add Element");
    print("2. Delete Element");
    print("3. Search Element");
    print("4. Exit");
    print("5. Display elements");

    String option = stdin.readLineSync()!;
    switch(option) {
      case "1":
        print("Enter the value to add: ");
        inputFromUser = stdin.readLineSync()!;
        listOfNumbers.add(int.parse(inputFromUser));
        break;
      case "2":
        print("Enter the value to delete: ");
        inputFromUser = stdin.readLineSync()!;
        listOfNumbers.remove(int.parse(inputFromUser));
        break;
      case "3":
        print("Enter the value to search: ");
        inputFromUser = stdin.readLineSync()!;
        int Index = listOfNumbers.indexOf(int.parse(inputFromUser));
        if (Index == -1) {
          print("Item does not exist");
        } else {
          print("The item is at index: "+Index.toString());
        }
        break;
      case "4":
        exit(0);
      case "5":
        print(listOfNumbers);
        break;
      default:
        print("Invalid input");
        break;
      
        

      // .remove(value)
      // [1 2 3 4 5] remove(3) [1 2 4 5]
      // [1 2 3 4 5] removeAt(3) [1 2 3 5]
      // [1 2 3 4 5] removeLast() [1 2 3 4]
      
      // [1 2 3 4 5] indexOf(3) => 2
      // indexOf(6) => -1
    }
  }

}

secondOccurenceInList.dart

void main() {
  List<int> numbers = [7, 8, 9, 8, 9];
  int firstIndex = numbers.indexOf(9);
  print("The second occurence of 9 is at: ");
  print(numbers.sublist(firstIndex+1).indexOf(9) + firstIndex + 1);

  // [7, 8, 9, 8, 9] firstIndex = 2
  // sublist(2) => [9,8,9]
  // sublist(3) => [8,9]
  //[8, 9] => indexOf(9) => 1
}