编辑代码

//程序4-4

import java.util.*;

class MyVector extends Vector {
    public MyVector() {
        super(1, 1); // 指定 capacity 和 capacityIncrement 取值
    }

    public void addInt(int i) {
        addElement(new Integer(i));
    }

    public void addFloat(float f) {
        addElement(new Float(f));
    }

    public void addString(String s) {
        addElement(s);
    }

    public void addCharArray(char a[]) {
        addElement(a);
    }

    public void printVector() {
        Object o;
        int length = size();  // 同capacity相比较

        System.out.println("Number of vector elements is " + length + " and they are:");
        for (int i = 0; i < length; i++) {
            o = elementAt(i);
            if (o instanceof char[]) {
//                System.out.println(o); // 打印数组地址
//                System.out.println(Arrays.toString((char[]) o));
                System.out.println(String.copyValueOf((char[]) o));
            } else
                System.out.println(o.toString());
        }
    }

    public static void main(String args[]) {
        MyVector v = new MyVector();
        int digit = 5;
        float real = 3.14f;
        char letters[] = {'a', 'b', 'c', 'd'};
        String s = new String("Hi there!");

        v.addInt(digit);
        v.addFloat(real);
        v.addString(s);
        v.addCharArray(letters);

        v.printVector();
    }
}