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());    }}}