I created a class, and I want to create some global arrays for this class in order to allow all methods of the class to use them. Problem is I don't know the size of the arrays in the first place. The size is based upon a file I read using JAVA's code. How can I define those arrays (Global) with the information I receive from the file?
我创建了一个类，我想为这个类创建一些全局数组，以便允许类的所有方法使用它们。问题是我首先不知道数组的大小。大小基于我使用JAVA代码读取的文件。如何使用从文件中收到的信息定义这些数组（全局）？
**Got no problem with reading the file itself and retrieve information from it.
**读取文件本身并从中检索信息没有问题。
Thanks :)
谢谢 ：）
1 个解决方案
#1
1
UPDATE: According to your comment, I had misunderstood your needs.
更新：根据你的评论，我误解了你的需求。
If your problem is just the array declaration, then this should probably solve it.
如果您的问题只是数组声明，那么这应该可以解决它。
You may declare your 2D-array this way as a "global" array(*):
您可以将这种2D数组声明为“全局”数组（*）：
private MyClass[][] myArray;
This won't initialize it, but declare its type as a 2D-array of MyClass objects.
这不会初始化它，而是将其类型声明为MyClass对象的2D数组。
Then when you start reading the file and you've got the size:
然后，当你开始阅读文件，你已经有了大小：
int size = /* read the size from the file */;
myArray = new MyClass[size][size];
It is unclear what you want to achieve.
目前还不清楚你想要达到什么目标。
If you want to dynamically add elements to an array and you don't know its size at initialization time, I would suggest you use an ArrayList:
如果你想动态地向数组添加元素而你在初始化时不知道它的大小，我建议你使用一个ArrayList：
ArrayList<SomeClassForYourData> list = new ArrayList<>();
To add an element:
要添加元素：
list.add(element);
To access element at index i:
要访问索引i处的元素：
SomeClassForYourData element = list.get(i);
To find the size of the structure:
要查找结构的大小：
int size = list.size();
#1
1
UPDATE: According to your comment, I had misunderstood your needs.
更新：根据你的评论，我误解了你的需求。
If your problem is just the array declaration, then this should probably solve it.
如果您的问题只是数组声明，那么这应该可以解决它。
You may declare your 2D-array this way as a "global" array(*):
您可以将这种2D数组声明为“全局”数组（*）：
private MyClass[][] myArray;
This won't initialize it, but declare its type as a 2D-array of MyClass objects.
这不会初始化它，而是将其类型声明为MyClass对象的2D数组。
Then when you start reading the file and you've got the size:
然后，当你开始阅读文件，你已经有了大小：
int size = /* read the size from the file */;
myArray = new MyClass[size][size];
It is unclear what you want to achieve.
目前还不清楚你想要达到什么目标。
If you want to dynamically add elements to an array and you don't know its size at initialization time, I would suggest you use an ArrayList:
如果你想动态地向数组添加元素而你在初始化时不知道它的大小，我建议你使用一个ArrayList：
ArrayList<SomeClassForYourData> list = new ArrayList<>();
To add an element:
要添加元素：
list.add(element);
To access element at index i:
要访问索引i处的元素：
SomeClassForYourData element = list.get(i);
To find the size of the structure:
要查找结构的大小：
int size = list.size();