java基础入门-iterator迭代器与集合下标的使用

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

public class Test {

public Test() {
// 初始化List
addItemToList();
}

private ArrayList<String> list = new ArrayList<String>();

private void addItemToList() {
for (int i = 0; i < 5; i++) {
list.add(i + "");
}
}

public ArrayList<String> getList() {
return list;
}

public void setList(ArrayList<String> list) {
this.list = list;
}

public static void main(String[] args) {
Test test1 = new Test();
ArrayList<String> test1List = test1.getList();
for (int i = 0; i < test1List.size(); i++) {
// 这里使用下标，直接指向元素
test1List.remove(i);
}
System.out.println("test1List have been removed all elements");
Test test2 = new Test();
ArrayList<String> test21List = test2.getList();
for (Iterator<String> iterator = test21List.iterator(); iterator
.hasNext();) {
// 使用迭代器对集合操作时,需要先做next()
// next()类似于游标，他是介于两个元素之间的
// 不像上面直接指向某个元素
iterator.next();
iterator.remove();
}
System.out.println("test2List have been removed all elements");
}
}