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

class Cat{
    String name;
    int age;
    Cat(String name,int age){
        this.name = name;
        this.age = age;
    }
    void show(){
        System.out.println(this.name+this.age);
    }
}
@SuppressWarnings
 
("unchecked")
public class TEST {

    @SuppressWarnings("rawtypes")
    public static void main(String[] args) {
        Collection c = new ArrayList();
        c.add("a");
        c.add("b");
        c.add("c");
        //1.集合變成陣列再進行遍歷
        Object[] arr = c.toArray();
        for (int i=0;i<arr.length;i++) {
            System.out
 
.println(arr[i]);
        }
        System.out.println("-----------------");
        //2.迭代器遍歷
        Iterator it = c.iterator();
        while(it.hasNext()){//判斷有沒有元素
            System.out.println(it.next());//取元素
        }
        System.out.println("-----------------");
        //3.遍歷自定義物件
        Collection c1 = new
 
 ArrayList();
        c1.add(new Cat ("小花",1));
        c1.add(new Cat ("大白",5));

        Iterator it1 = c1.iterator();//裡面的物件都會自動提升為Object類
        while(it1.hasNext()){
            Cat cat = (Cat)it1.next();
            cat.show();

        }

    }

}