Java使用迭代器Iterator遍历集合

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
/**
 * @Author：Aniu
 * @Date：2022/12/6 11:51
 * @description TODO
 */
public class Demo {
    public static void main(String[] args) {
        Collection coll = new ArrayList();
        coll.add("aniu");
        coll.add(123); //自动装箱
        coll.add(new String("miao"));

        // 遍历集合
        Iterator iterator1 = coll.iterator();
        // 方式一：利用 for 循环 -》不推荐
        for(int i=0;i<coll.size();i++){
            System.out.println(iterator1.next());
        }

        System.out.println("-----------");

        // 方式二 ：利用 while 循环 -》推荐
        Iterator iterator2 = coll.iterator();
        while(iterator2.hasNext()){
            System.out.println(iterator2.next());
        }
    }
}

Collection coll = new ArrayList();
coll.add("aniu");
coll.add(123); //自动装箱
coll.add(new String("miao"));
// 删除"miao"
Iterator iterator = coll.iterator();
while(iterator.hasNext()){
    Object obj = iterator.next();
    if("miao".equals(obj)){
        iterator.remove(); // 删除"miao"
    }
}

System.out.println(coll);

Iterator iterator = coll.iterator();
while(iterator.hasNext()){ //hasnext() 判断是否还有下一个元素
    System.out.println(iterator.next()); //next 1.指针下移 2.将下移以后集合位置上的元素返回
}

// for(datatype 变量名 : 遍历对象)
for(Object obj:coll){
   System.out.println(obj);
}

String[] arr = new String[]{"aniu","haha","zz"};
for(int i=0;i<arr.length;i++){
    arr[i] = "momo";
}
for(int i=0;i<arr.length;i++){
    System.out.println(arr[i]);
}

System.out.println("----------");

String[] arr1 = new String[]{"aniu","haha","zz"};
for (String str:arr1){
    str = "momo";
}
for(int i=0;i<arr1.length;i++){
    System.out.println(arr1[i]);
}