package learning;

import java.util.ArrayList;

public class ClassExample {

    class index {
        String material;
        double quantity;
    }

    public static void main(String[] args) {
        ArrayList<index> display = new ArrayList<index>();
        String x = null;
        double y = 0;
        index adding = new index();
        adding.material = x;
        adding.quantity = y;
        display.add(adding);
    }

}