arraylistdemo.java~2~

java2参考大全上的例子的源码和自己的理解.

package arraylist;

/**
 该程序的输出如下所示：

 Initial size of al: 0
 Size of al after additions: 7
 Contents of al: [C, A2, A, E, B, D, F]
 Size of al after deletions: 5
 Contents of al: [C, A2, E, B, D]
 */

// Demonstrate ArrayList.
import java.util.*;

class ArrayListDemo {
  public static void main(String args[]) {
    // create an array list
    ArrayList al = new ArrayList();

    System.out.println("Initial size of al: " +
                       al.size());

    // add elements to the array list
    al.add("C");
    al.add("A");
    al.add("E");
    al.add("B");
    al.add("D");
    al.add("F");
    al.add(1, "A2");

    System.out.println("Size of al after additions: " +
                       al.size());

    // display the array list
    System.out.println("Contents of al: " + al);

    // Remove elements from the array list
    al.remove("F");
    al.remove(2);

    System.out.println("Size of al after deletions: " +
                       al.size());
    System.out.println("Contents of al: " + al);
  }
}