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Java基礎-集合Collection遍歷的方式

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) {
        // 遍歷集合Collection元素物件的方法


        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:先指向集合第一個元素物件前 -> 依次往下遍歷 Iterator iterator = collection.iterator();
while (iterator.hasNext()) { Object next = iterator.next(); System.out.println("next = " + next); } System.out.println("============================="); // 2、增強for迴圈:底層同樣是迭代器 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 + '}'; } }