Java中的向量类

2024-04-18 22:32:03 353

向量的优点

向量可以容纳不同类的对象。

向量是同步的。

向量的缺点

向量慢

让我们使用以下示例更清楚地了解vector：

package logicProgramming;
import java.util.Vector;

//学生类 
class Student
{
	//类的数据成员	
	private int rollno;
	private String name;
	private String schoolCode;

	//构造函数
	public Student(int rollno,String name,String schoolcode)
	{  
		this.rollno=rollno;
		this.name=name;
		this.schoolCode=schoolcode;
	}
	//putStudent()打印学生对象的值
	public void putStudent()
	{
		System.out.println("RollNo :"+this.rollno+"\nName :"+this.rollno+"\nSchoolCode :"+this.schoolCode);	 
	}
}

//代表员工的类
class CompanyEmployee
{
	//该类的数据成员
	public int id;
	public String name;
	public long salary;
	//构造函数
	public CompanyEmployee(int id,String name,long salary)
	{
		this.id=id;
		this.name=name; 
		this.salary=salary;
	}
	//putEmployee()打印出雇员对象的值
	public void putEmployee()
	{
		System.out.println("Id :"+this.id+"\nName :"+this.name+"\nSalary :"+this.salary);	 
	}
}

//主类 
public class ExVector {
	public static void main(String[] args) {	
		Vector V=new Vector(); //持有对象的矢量类
		V.add(new CompanyEmployee(100,"Harendra Chekkur",34000)); //将CompanyEmployee对象添加到Vector- 
		V.add(new Student(10,"Madhav Singh","CB2025"));  //将Student对象添加到Vector-
		V.add(new Integer(70));    //将整数作为对象添加到Vector-
		V.add(new String("Testing Vectors")); ////将String作为对象添加到Vector-
		V.add(new Float(57.4)); ////将员工作为对象添加到Vector-

		//迭代向量以打印对象 
		for(Object O:V)
		{   
			/* as Vector holds hetrogeneous data objects thus we have to cast the object to it's type
			in order to do this we are using getName() function which gets the name of the class of the given object 
			and compares it with the given class , if it's matches than typecast the object to that class */
			if(O.getClass().getName().equals("logicProgramming.CompanyEmployee"))
			{
				System.out.println();
				((CompanyEmployee)O).putEmployee();
			}
			else if(O.getClass().getName().equals("logicProgramming.Student"))
			{  
				System.out.println();
				((Student)O).putStudent();
			}
			//如果找不到匹配项，我们将只打印对象 
			else
			{ 
				System.out.println();
				System.out.println(O);
			}
		}  
	}
}

输出结果

Id :100
Name :Harendra Chekkur
Salary :34000

RollNo :10
Name :10
SchoolCode :CB2025

70

Testing Vectors

57.4

Java中的向量类

向量的优点

向量的缺点

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