我有一个像这样的ArrayList:
[5, 181, 138, 95, 136, 179]
我想做的是将此列表转换为double []。这样的事情。
double[] Fails = new double[]{5, 181, 138, 95, 136, 179};
这是我的代码:
ArrayList<String> DatesList = new ArrayList<String>();
ArrayList<String> FailList = new ArrayList<String>();
while (rs2.next()) {
DatesList.add(rs2.getString("Date"));
FailList.add(rs2.getString("fail"));
}
double[] Fails = new double[]{FailList}; //obviously it doesn't work..
有没有办法从ArrayList转换为double []?
答案 0 :(得分:4)
List<String> failList = new ArrayList<>();
while (rs2.next()) { //whatever that is (copied from OP)
failList.add(rs2.getString("fail"));
}
double[] failsArray = new double[failList.size()]; //create an array with the size of the failList
for (int i = 0; i < failList.size(); ++i) { //iterate over the elements of the list
failsArray[i] = Double.parseDouble(failList.get(i)); //store each element as a double in the array
}
此代码的作用是,它首先创建一个大小为failsArray
的数组failList
。然后,它迭代failList
并将每个项解析为double,并将其存储在failsArray
中。