PolymorphismEx5.java

package com.study.polymorphism;

import java.util.*;

public class PolymorphismEx5 {

    static int getSum(List<Integer> list) {
        int sum = 0;
        for(Integer i : list) sum = sum + i;
        return sum;
    }

    static void addRandomValue(List<Integer> list, int count) {
        Random random = new Random();
        for(int i=0; i < count; ++i) list.add(random.nextInt(20));
    }

    public static void main(String[] args) {
        ArrayList<Integer> list1 = new ArrayList<>();
        LinkedList<Integer> list2 = new LinkedList<>();
        Vector<Integer> list3 = new Vector<>();

        addRandomValue(list1, 10);
        addRandomValue(list2, 10);
        addRandomValue(list3, 10);

        System.out.printf("%s 합계: %d\n", list1.toString(), getSum(list1));
        System.out.printf("%s 합계: %d\n", list2.toString(), getSum(list2));
        System.out.printf("%s 합계: %d\n", list3.toString(), getSum(list3));

    }

}