java - 尝试在Java中向数组添加多个 double

我正在尝试将购买列表添加到数组中，然后能够基于数组中的双打执行一些计算。我在尝试向双阵列添加购买时遇到麻烦
这是我所拥有的：

public abstract class Customer {

   protected String category;
   protected String acctNumber;
   protected String name;
   protected double[] purchases;
   protected static final double SALES_TAX_RATE = 0.08;

/**
*Reads in customer data.
*@param acctNumberIn customers account number.
*@param nameIn customers name.
*/
   public Customer(String acctNumberIn, String nameIn) {

      acctNumber = acctNumberIn;
      name = nameIn;
      purchases = new double[0];

   }

在遇到问题时添加购买方式：

public void addPurchases(double ... pur) {


      purchases = Arrays.copyOf(purchases, purchases.length + 1);
      int a = purchases.length;
      for (int i = 0; i < purchases.length; i++) {
         purchases[a] = pur;
         }


   }

最佳答案

问题在于pur的类型为double []。因此，您将需要创建一个采购数量为pur的新数组，并将每个pur元素复制到采购结束。

请尝试以下代码：

public void addPurchases(double ... pur) {
  int purchasesLength = purchases.length;
  int combinedLength = pur.length + purchasesLength;
  purchases = Arrays.copyOf(purchases, combinedLength);
  for (int i = purchasesLength, j = 0; i < combinedLength; i++, j++) {
     purchases[i] = pur[j];
  }
}