用Vector 来实现动态的数组
定义Vector v = new Vector();
v.addElement("str");
v.size();
v.removeElement(0);
等很多的方法
具体的可查看Api
定义Vector v = new Vector();
v.addElement("str");
v.size();
v.removeElement(0);
等很多的方法
具体的可查看Api
只能用Vector,ArrayList之类的类来实现,或者转一下。
ArrayList myList = new ArrayList();添加成员可用
int index;
Date day;
myList.add(inex,day)//index为添加的对象,在list中的编号,day的位置可以是任意的类的对象取得成员可用
day = (Date)myList.get(index);//取得第index个对象,注意,提取出来后要进行强制类型转换
我是一个初学者。比如我用Math.random()取得随机的n长的数组。n是从键盘输入的,请给我代码好吗???谢谢。
public static void main (String args[]){
//initial size is 3,increment is 2
Vector v=new Vector(3,2);
System.out.println("Initial size: " +v.size());
System.out.println("Initial capacity: "+v.capacity());
v.addElement(new Integer(1));
v.addElement(new Integer(2));
v.addElement(new Integer(3));
v.addElement(new Integer(4));
System.out.println("Capacity after four addition: "+ v.capacity());
v.addElement(new Double(5.45));
System.out.println("Current Capacity : "+ v.capacity());
v.addElement(new Double(6.08));
v.addElement(new Integer(7));
System.out.println("Current Capcity: "+v.capacity());
v.addElement(new Float(9.4));
v.addElement(new Integer(10));
System.out.println("Curerent Capacity: "+v.capacity());
v.addElement(new Integer(11));
v.addElement(new Integer(12));
System.out.println("First element: "+(Integer)v.firstElement());
System.out.println("Last elemnet: "+(Integer)v.lastElement());
if (v.contains(new Integer(3)))
System.out.println("Vector contains 3.");
//begin here -->
//enumerate the elments in the vector.
Enumeration vEnum=v.elements();
System.out.println("\nElements in vector: ");
while(vEnum.hasMoreElements())
System.out.print(vEnum.nextElement() + " ");
System.out.println();
//end here <-- can be replace by the code under
Iterator itr=v.iterator();
System.out.println("\nElements in vector: ");
while(itr.hasNext())
System.out.print(itr.next()+ " ");
System.out.println();
}
}