Vector的使用

import java.util.Enumeration;
import java.util.Vector;

public  class Demo01 {
    public static void main(String[] args) {
        Vector:数组结构实现，查询快。增删慢 ；运行效率慢，线程安全
       
        //创建集合
        Vector vector = new Vector<>();

        //1.添加元素
        Student s1 = new Student("张三", 16);
        Student s2 = new Student("李四", 16);
        Student s3 = new Student("王五", 16);
        vector.add(s1);
        vector.add(s2);
        vector.add(s3);
        System.out.println("元素个数："+vector.size());//元素个数：3
        System.out.println(vector);//[Student{name='张三', age=16}, Student{name='李四', age=16}, Student{name='王五', age=16}]

        //2.删除元素
        vector.remove(s1);
        System.out.println("元素个数："+vector.size());//元素个数：2
        System.out.println(vector);//[Student{name='李四', age=16}, Student{name='王五', age=16}]

        //3.遍历
          //使用枚举器
        Enumeration elements = vector.elements();
        while (elements.hasMoreElements()){
            System.out.println(elements.nextElement());
        }

        //4.判断
        System.out.println(vector.contains(s2));//true
        System.out.println(vector.isEmpty());//false

        //5.其他方法
        System.out.println(vector.firstElement());//Student{name='李四', age=16}
        System.out.println(vector.lastElement());//Student{name='王五', age=16}
        System.out.println(vector.elementAt(0));//Student{name='李四', age=16}
    }
}

public class Student {
    private String name;
    private int age;

    public Student() {

    }

    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

    @Override
    public boolean equals(Object obj) {
        //1.判断是否为空
        if(obj==null){
            return false;
        }
        //2.判断是否为同一个对象
        if(obj==this){
            return  true;
        }
        //判断是否可转为Student类型
        if(obj instanceof Student){
            Student s=(Student) obj;//强转
            if(this.name.equals(s.getName())&&this.age==s.getAge()){
                return true;
            }
        }
        return false;
    }
}