package com.bo.collection;
//Collection
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

public class Demo02 {
    public static void main(String[] args) {
        Collection collection = new ArrayList();

        Student s1 = new Student("赵",20);
        Student s2 = new Student("钱",21);
        Student s3 = new Student("孙",22);
        //添加数据
        collection.add(s1);
        collection.add(s2);
        collection.add(s3);
        collection.add(s3);
        System.out.println("元素个数："+collection.size());
        System.out.println(collection.toString());
        //删除
        collection.remove(s1);
        //从集合中清楚collection.clear(); 对象不会消失消失的是集合里对象的地址
        System.out.println("删除之后："+collection.size());
        //遍历
        //增强for
        for (Object objcet:collection ){
            Student s =(Student) objcet;
            System.out.println(s);
        }
        System.out.println("------------------------");
        //迭代器
        Iterator it = collection.iterator();
        while(it.hasNext()){
           Student s= (Student) it.next();
            System.out.println(s);
        }
        //判断
        System.out.println(collection.contains(s2));
        System.out.println(collection.isEmpty());

    }
}

package com.bo.collection;

import java.util.Objects;

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 o) {
        if (this == o) return true;//判断是不是同一个对象
        if (o == null ) return false;//判断是否为空
        //判断是否是Student类型
        if (o instanceof Student){
            Student s =(Student) o;
            if (this.name.equals(s.getName())&&this.age== s.getAge());
            return true;}
        return false;//不满足条件返回false
    }


}