package com.hspedu.collection_; import java.util.ArrayList; import java.util.Collection; import java.util.Iterator; @SuppressWarnings({"all"}) public class Course501 { public static void main(String[] args) { // 遍历集合Collection元素对象的方法 Collection collection = new ArrayList(); collection.add(new Cat("小白", 3)); collection.add(new Cat("小黑", 5)); collection.add(new Cat("小花", 2)); collection.add("Tom"); collection.add("Mary"); collection.add(100); collection.add(200); // 1、迭代器iterator:先指向集合第一个元素对象前 -> 依次往下遍历 Iterator iterator = collection.iterator(); while (iterator.hasNext()) { Object next = iterator.next(); System.out.println("next = " + next); } System.out.println("============================="); // 2、增强for循环:底层同样是迭代器 for (Object object : collection) { System.out.println("object = " + object); } } } class Cat { private String name; private int age; public Cat(String name, int age) { this.name = name; this.age = age; } @Override public String toString() { return "Cat{" + "name='" + name + '\'' + ", age=" + age + '}'; } }