Java_基础—集合的遍历之迭代器遍历

package com.soar.collection;

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

import com.soar.bean.Student;

@SuppressWarnings({ "rawtypes", "unchecked" })
public class Demo5_Iterator {
/*
*   * A:迭代器概述
    * 集合是用来存储元素,存储的元素需要查看,那么就需要迭代(遍历) 
    * B:案例演示
    * 迭代器的使用
 */
    public static void main(String[] args) {
        //demo1_Iterator();
        Collection c = new ArrayList();
        c.add(new Student("张三",23));        //Object obj = new Student("张三"，23);
        c.add(new Student("李四",24));
        c.add(new Student("王五",25));
        c.add(new Student("赵六",26));

        //获取迭代器
        Iterator it = c.iterator();
        while(it.hasNext()){
            //System.out.println(it.next());    //toString方法
            Student s = (Student)it.next();     //向下转型
            System.out.println(s.getName()+"..."+s.getAge());
        }
    }

private static void demo1_Iterator() {
    Collection c = new ArrayList();
    c.add("a");
    c.add("b");
    c.add("c");
    c.add("d");

    //对集合中的元素进行迭代（遍历）
    Iterator it = c.iterator();     //获取迭代器

/*      boolean b1 = it.hasNext();      //判断集合中是否有元素，有就返回true
    Object obj1 = it.next();
    System.out.println(b1);     //true
    System.out.println(obj1);   //a

    boolean b2 = it.hasNext();      //判断集合中是否有元素，有就返回true
    Object obj2 = it.next();
    System.out.println(b2);     //true
    System.out.println(obj2);   //b     
*/  
    while(it.hasNext()){
        System.out.println(it.next());
    }
}
}