您需要通过指数来解决这个问题：

You need to address it by index:

arr[2] = "new york";

既然你说你不知道的位置，你可以使用Array.IndexOf找到它：

Since you say you don't know the position, you can use Array.IndexOf to find it:

arr[Array.IndexOf(arr, "paris")] = "new york";  // ignoring error handling