Java 大小在 ArrayList 中具有私有访问权限
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Size has private access in ArrayList
提问by eggHunter
I wrote a pretty standard bit of code utilizing String populated ArrayListbut when I try running it, I get the following error:
我使用填充的字符串编写了一段非常标准的代码，ArrayList但是当我尝试运行它时，出现以下错误：
error: size has private access in ArrayList.
error: size has private access in ArrayList.
The code is as follows:
代码如下：
System.out.println(testedArticles.size);
采纳答案by Richard Tingle
You are attempting to access a private member of ArrayList, part of its internal working that are not supposed to be used externally
您正试图访问 的私有成员ArrayList，其内部工作的一部分不应在外部使用
If you want to get the size of the arraylist you want the method:
如果你想获得你想要的方法的数组列表的大小：
arraylist.size()
Why is it like this
为什么会这样
This gives the ArrayListclass the option to store size in whatever way it wants. Does it just return size, probably, but it could do a number of other things instead. For example it could calculate size lazily, in which it is only calculated if someone asked for it then it stores that value until it becomes invalid (as more objects are added). This would be useful if calculating size was expensive (very unlikely to be the case here), changed often and was called only occasionally.
这使ArrayList类可以选择以任何方式存储大小。它是否只是 return size，可能，但它可以做许多其他事情。例如，它可以懒惰地计算大小，其中只有在有人要求时才计算它，然后它会存储该值，直到它变得无效（随着更多对象的添加）。如果计算大小很昂贵（这里不太可能是这种情况），经常更改并且只是偶尔调用，这将很有用。
回答by Prabhakaran Ramaswamy
There is nothing like ArrayList.size.You need to use .size()method.
没有什么像 ArrayList.size.你需要使用.size()方法。
You need to use
你需要使用
System.out.println(testedArticles.size());
instead of
代替
System.out.println(testedArticles.size);
