練習解答

• 練習１
• 練習2
• 練習3

練習１

先在另一個包建立程式碼，命名為ch6Ex1.java

package ch5;

public class ch6Ex1 {
    public ch6Ex1(){
        System.out.println("hello world");
    }
}

練習2

先定義一個Vector.java:

package ch6.Exercise2;

public class Vector {
    public Vector(){
        System.out.println("ch6.Exercise2.Vector");
    }
}

 

再定義一個Ex2.java:

package ch6.Exercise2;
import java.util.Vector;
import ch6.Exercise2.*;
public class Ex2 {
    public static void main(String[] args) {
//        Vector v = new Vector(); // ambiguous
        java.util.Vector v = new java.util.Vector();
        ch6.Exercise2.Vector v2 = new ch6.Exercise2.Vector();
    }
}

/**
 * output:
 * ch6.Exercise2.Vector
 *
 * Process finished with exit code 0
 * **/

 

練習3