java 将双数组列表转换为双数组
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Converting a Double Array list to a double array
提问by sam
I am wanting to convert my double ArrayList to a double array but I am unsure how. Here is my current code listing :
我想将我的双 ArrayList 转换为双数组，但我不确定如何。这是我当前的代码清单：
ArrayList<Double> aL= new ArrayList<Double>();
double x[] = new double[aL.size()];
aL.add(10.0);
aL.add(5.0);
aL.add(2.0);
for(int i =0; i < x.length; i++){
//some code
}
But then I am not sure where to go and I am unable to find something on the internet/ in books to give me any insight. Thanks.
但是后来我不知道该去哪里，而且我无法在互联网/书中找到一些东西来给我任何见解。谢谢。
采纳答案by Gilbert Le Blanc
First, you need to create your ArrayList. Then you need to create your array.
首先，您需要创建您的 ArrayList。然后你需要创建你的数组。
List<Double> aL= new ArrayList<Double>();
aL.add(10.0D);
aL.add(5.0D);
aL.add(2.0D);
double x[] = new double[aL.size()];
for(int i = 0; i < x.length; i++){
x[i] = al.get(i);
}
You can use an ArrayList method to copy the ArrayList to an array.
您可以使用 ArrayList 方法将 ArrayList 复制到数组。
List<Double> aL= new ArrayList<Double>();
aL.add(10.0D);
aL.add(5.0D);
aL.add(2.0D);
double x[] = aL.toArray();
回答by Sudhanshu Umalkar
You can use Collection API to convert list to array. Try uL.toArray();
您可以使用 Collection API 将列表转换为数组。试试 uL.toArray();
