java program to pass an ArrayList as a parameter in a method and perform diff. operation on it.

import java.util.*;

public class HelloWorld {

public static void printlist(ArrayList<Integer> list)
{
System.out.println(list);
}
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);

  ArrayList<Integer> list=new ArrayList<Integer>();
  int n=sc.nextInt();
  while(n!=0)
  {
    switch(n)
    {
      case 1:
        int num=sc.nextInt();
        list.add(num);
        break;
      case 2:
        list.remove(list.size()-1);
        break;
      case 3:
        printlist(list);
        break;
      case 4:
        Collections.sort(list);
        break;
      case 0:
        System.exit(0);
      default:
        System.out.println("Please enter a valid number.");
        break;
    }
    n=sc.nextInt();
  }
  
}

}