示例如下: import java.util.*; import java.io.*; class myVector extends Vector{ public myVector() { super(1,1); } 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 findVector(){ Object o; for(int i=0;i<size();i++) { o=elementAt(i); if(o instanceof Float) System.out.println(o+" is located at index "+this.indexOf(o)); //else //System.out.println("not found in vector"); // remove(o); // System.out.println("Elements "+o+" successfully deleted from vector");}
} } public void printVector(){ Object o; int length=size(); 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[]) //判断o是否是char[]的实例 { System.out.println((char[])o);//don't use toString() method } else System.out.println(o.toString());
} } public static void main(String[] args) throws Exception{ 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.findVector(); v.printVector();
import java.util.*;
import java.io.*;
class myVector extends Vector{
public myVector()
{
super(1,1);
}
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 findVector(){
Object o;
for(int i=0;i<size();i++)
{
o=elementAt(i);
if(o instanceof Float)
System.out.println(o+" is located at index "+this.indexOf(o));
//else
//System.out.println("not found in vector");
// remove(o);
// System.out.println("Elements "+o+" successfully deleted from vector");}
}
}
public void printVector(){
Object o;
int length=size();
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[]) //判断o是否是char[]的实例
{
System.out.println((char[])o);//don't use toString() method
}
else
System.out.println(o.toString());
}
}
public static void main(String[] args) throws Exception{
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.findVector();
v.printVector();
}
}
一.同步性:Vector是线程安全的,也就是说是同步的,而ArrayList是线程序不安全的,不是同步的
二.数据增长:当需要增长时,Vector默认增长为原来一培,而ArrayList却是原来的一半
Vertor是jdk1.2以后不建议使用的,尽量用ArrayList
是线程安全,但是这也使的他在效率上比较差
运行时间比较长
boolean boo=false; //boolean 是布尔类型,布尔是不是这样写的boolean?你们能看懂就行了
v.addElement(boo);
请问这个程序对吗?
怎么修改这个程序?
Vector v=new Vector();
boolean boo=false; //boolean 是布尔类型,布尔是不是这样写的boolean?你们能看懂就行了
v.addElement(boo);
请问这个程序对吗?
怎么修改这个程序?