ArrayList的一点研究

public class ArrayListTest {
    public static void main(String[] args) {
        ArrayListTest.test3();
    }

    // 抛异常，重复的时候不准可删除元素
    public static void test1() {
        List<String> reList = new ArrayList<String>();
        reList.add("1");
        reList.add("2");
        reList.add("3");
        reList.add("4");
        for (String s : reList) {
            if (s.equals("2")) {
                reList.remove(s);
            }
        }
        System.out.println(reList.toString());
    }

    // 抛异常,通过这类方法创立的List不准可变革长度
    public static void test2() {
        List<String> reList = Arrays.asList("1", "2", "3", "4");
        reList.add("5");
        System.out.println(reList.toString());
    }

    // 通过迭代器可以在重复的时候删除
    public static void test3() {
        List<String> reList = new ArrayList<String>();
        reList.add("1");
        reList.add("2");
        reList.add("3");
        reList.add("4");
        Iterator<String> it = reList.iterator();
        while (it.hasNext()) {
            String i = it.next();
            if (i.equals("2")) {
                it.remove();
            }
        }
        System.out.println(reList.toString());
    }
}
public class ArrayListTest {
    public static vo