how to add at a certain position in java code example

Example 1: java insert into arraylist

ArrayList<Integer> str=new ArrayList<Integer>();
str.add(0);
str.add(1);
 // Result = [0, 1]
    
str.add(1, 11);
 // Result = [0, 11, 1]

Example 2: java insert element at position

package com.tutorialspoint;

import java.util.ArrayList;

public class ArrayListDemo {
   public static void main(String[] args) {

      // create an empty array list with an initial capacity
      ArrayList<Integer> arrlist = new ArrayList<Integer>(5);

      // use add() method to add elements in the list
      arrlist.add(15);
      arrlist.add(22);
      arrlist.add(30);
      arrlist.add(40);

      // adding element 25 at third position
      arrlist.add(2,25);
        
      // let us print all the elements available in list
      for (Integer number : arrlist) {
         System.out.println("Number = " + number);
      }  
   }
}