JavaSE框架之Collection集合方法

Collection方法。

1，add(Object o)；
2，size()；
3，contains()；其底层调用的是equals方法。
4，toArray()；
5，isEmpty()；
6，remove()；
7，interator()；

迭代器，含三个方法，
hasNext()；
next()；
remove()；（移除迭代器指向的collection的最后一个元素。）

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

public class Test01 {

	public static void main(String[] args) {
		Student s1 = new Student("张三", 23);
		Student s2 = new Student("李四", 23);
		Student s3 = new Student("王五", 23);
		Collection collection = new ArrayList();
		// 向collection中添加元素
		collection.add(s1);
		collection.add(s2);
		collection.add(s3);
		System.out.println("collection的长度为" + collection.size());
		System.out.println("collection是否为空" + collection.isEmpty());
		System.out.println("collection的" + collection.size());
		Object[] array = collection.toArray();
		int i = 0;
		while (i < array.length) {
			System.out.println("姓名:" + ((Student) array[i]).getName() + ",年龄:" + ((Student) array[i]).getAge());
			i++;
		}
		System.out.println("collection中是否含有s2" + collection.contains(s2));
		System.out.println("---------------------------------");
		Iterator iterator = collection.iterator();
		while (iterator.hasNext()) {
			Student next = (Student) iterator.next();
			System.out.println("姓名:" + next.getName() + ",年龄:" + next.getAge());
			iterator.remove();
		}
		System.out.println("collection中是否含有s2" + collection.contains(s2));
		System.out.println("collection是否为空" + collection.isEmpty());
	}

}

class Student {
	private String name;
	private int 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;
	}

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

}