如何将 java ArrayList<Double> 转换为等效的 double[]
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How do I convert a java ArrayList<Double> to the equivalent double[]
提问by deltanovember
Possible Duplicate:
How to cast from List<Double> to double[] in Java?
So far the only method I can get working is to loop through the entire array. I was hoping for something along the lines of:
到目前为止，我可以使用的唯一方法是遍历整个数组。我希望有以下几点：
ArrayList<Double> myArrayList = ... // initiaize
double[] myArray = ... // magic line here
回答by lschin
回答by Yanick Rochon
You cannot go from ArrayList<Double>to double[]with a single call using the sandard Java API. However, take a look at the ArrayUtilsclass available from Apache's site.
你不能从去ArrayList<Double>到double[]使用的sandard Java API的一个调用。但是，请查看Apache 站点上提供的ArrayUtils类。
On a side note, if you need to change your ArrayListinto a primitive array, perhaps your problem is somewhere else. If you explain further exactly what you are trying to achieve, we could provide you better help than a simple API hack.
附带说明一下，如果您需要将您ArrayList的数组更改为原始数组，那么您的问题可能出在其他地方。如果您进一步准确地解释您要实现的目标，我们可以为您提供比简单的 API hack 更好的帮助。
