My code works and conditions satisfied , but why we do not need return statement ?

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int[] AddressOfArray = new int[20];
        for (int i = 0; i < 20; i++) {
            AddressOfArray[i] = Integer.parseInt(reader.readLine());
        }

        sort(AddressOfArray);

        for (int x : AddressOfArray) {
            System.out.println(x);
        }
    }

    public static void sort(int[] passedAddressOfArray) {
        ArrayList<Integer> number = new ArrayList<Integer>();

        for (int x : passedAddressOfArray) number.add(x);

        Collections.sort(number);
        Collections.reverse(number);

        for (int i = 0; i < number.size(); i++)
          passedAddressOfArray[i] = number.get(i);
    }
}