你做得很好，我没有看到问题，但我认为 arraylists 存储对象，所以如果你想要一个整数，请构建一个对象.我想如果你能编译它，这会自动完成.

You're doing ok, I don't see a question but I think that arraylists store objects, so if you want an integer, get build an object. I guess if you can compli that, this is done automatically.

Integer i = new Integer(1);
myList.add(i);

或在 1 行中

myList.add(new Integer(1));

正如 Paul Bellora 所说，new Integer(i) 是不必要的，你可以只用 i 替换它.我只是想指出 ArrayLists store objects(不知何故我忘了提到这一点)，而不是像 int 这样的原始数据类型，当你尝试这样做时，数据是如果可能的话(对编译器)转换为 Object 的子对象，就像 Integer 一样.

As Paul Bellora says, new Integer(i) is unnecessary and you can replace it with just i. I just wanted to point out that ArrayLists store objects (somehow i forgot to mention that), not primitive data types like int and when you try to do it, the data is converted if possible (to the compiler) to a child of Object just like Integer.