我试图了解Java Iterator和Iterable接口

我正在写这堂课

class MyClass implements Iterable<String> {
    public String[] a = null;
    public MyClass(String[] arr) {
        a = arr;    
    }

    public MyClassIterator iterator() {
        return new MyClassIterator(this);
    }

    public class MyClassIterator implements Iterator<String> {
        private MyClass myclass = null;
        private int count = 0;
        public MyClassIterator(MyClass m) {
            myclass = m;    
        }

        public boolean hasNext() {
            return count < myclass.a.length;
        }
        public String next() {
            int t = count;
            count++;
            return myclass.a[t];
        }

        public void remove() {
            throw new UnsupportedOperationException();
        }
    }   
}

它似乎正在工作。

我应该有：

Myclass implements Iterable<Stirng>, Iterator<String> {

}

或者我应该把MyClassIterator外面MyClass的

class MyClass implements Iterable<String> {
    public String[] a = null;
    public MyClass(String[] arr) {
        a = arr;    
    }
    public MyClassIterator iterator() {
        return new MyClassIterator(this);
    }
}


    public class MyClassIterator implements Iterator<String> {
        private MyClass myclass = null;
        private int count = 0;
        public MyClassIterator(MyClass m) {
            myclass = m;    
        }

        public boolean hasNext() {
            return count < myclass.a.length;
        }
        public String next() {
            int t = count;
            count++;
            return myclass.a[t];
        }

        public void remove() {
            throw new UnsupportedOperationException();
        }
    }

哪一个更好？