如何使用 ArrayList.addAll()? [英] How to use ArrayList.addAll()?

问题描述

我想用这些字符 +、-、*、^ 等填充 ArrayList.如何做到这一点而不必用 arrayList.add()?

I want to fill an ArrayList with these characters +,-,*,^ etc. How can I do this without having to add every character with arrayList.add()?

推荐答案

Collections.addAll 就是你想要的.

Collections.addAll(myArrayList, '+', '-', '*', '^');

另一种选择是使用 Arrays.asList 像这样:

Another option is to pass the list into the constructor using Arrays.asList like this:

List<Character> myArrayList = new ArrayList<Character>(Arrays.asList('+', '-', '*', '^'));

但是，如果您对固定长度的 arrayList 感到满意，则可以像 list = Arrays.asList(...) 那样简单地进行创建.Arrays.asList 规范指出它返回一个固定长度列表，该列表充当传递数组的桥梁，这可能不是您需要的.

If, however, you are good with the arrayList being fixed-length, you can go with the creation as simple as list = Arrays.asList(...). Arrays.asList specification states that it returns a fixed-length list which acts as a bridge to the passed array, which could be not what you need.

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