0x01 - c#自问自答 - yield

class czList : IEnumerable
{
    private int[] array = new int[10] { 1,2,3,4,5,6,7,8,9,10};

    public IEnumerator GetEnumerator()
    {
        yield return "Hello";
        yield return "World";
        for (int i = 0; i < 10; i++)
        {
            if (i < 5)
                yield return array[i];
            else
                yield break;
                // break 会切断后续的return
        }
    }
}

var data = new czList();
foreach (var item in data)
{
    Console.WriteLine(item);//这里的item识别出来是object
    //yield会按yield return 顺序，依次返回相应的object
}
//out:Hello
//out:World
//out:1
//out:2
//out:3
//out:4
//out:5