Finding Perfect Squares from an ArrayList

I am trying to write code in java to find all numbers that are perfect squares from an array list and print out each number that is a perfect square in a new list, but I am getting incorrect outputs. Can you please help?

This is my code so far:

import java.util.Scanner;
import java.util.ArrayList;
public class MakeALibraryProject {
    public static ArrayList<Integer> perfectSquares(ArrayList<Integer> nums, double sqrt) {
        //Parameters: The list of the numbers 1-1000.
        for (int i = 1; i <= 1000; i++) {
            nums.add(i);
        }
        System.out.println(nums);
        //Return value: Returns all numbers from the list that are perfect squares.
        for (int i = nums.size() - 1; i >= 0; i--)  {
            sqrt = Math.sqrt(i);
            if (!(Math.floor(sqrt) == Math.ceil(sqrt))) {
                nums.remove(i);
            }
        }
        return nums;
    }
    public static void main(String[] args) {
        //Variable initialization
        ArrayList<Integer> nums = new ArrayList<Integer>();
        double sqrt = 0;
        //Function call
        System.out.println(perfectSquares(nums, sqrt));
    }
}

>Solution :

The issue is on the line

sqrt = Math.sqrt(i);

You aren’t checking the number you put in the list, but the index of the number. Replace it with

sqrt = Math.sqrt(nums.get(i));

and you’ll get what you expect.