發現兩年前寫的程式碼與題目要求有較大出入（看來當時沒搞清楚變長引數列表是怎麼回事），改進如下：使用變長陣列作為連乘方法的引數列表（注意public static double multiply(double... factors)一句中的省略號即表示變長引數）。

之前的程式碼參考：

https://blog.csdn.net/hpdlzu80100/article/details/51851067

程式碼如下：

package exercises.ch7Arrays;

	//JHTP Exercise 7.14: Variable-Length Argument List
	//by [email protected]
 

	/**(Variable-Length Argument List) Write an application that calculates the product of a series
	of integers that are passed to method product using a variable-length argument list. Test your method
	with several calls, each with a different number of arguments.*/
	 
	public class VariableLengthArgList
	{
		public static double multiply(double... factors){  //Using variable-length argument lists.
			double result=1.0;
			for (double f:factors)
				result*=f;
			return result;
		}
		
		public static void main(String[] args)
	{
		      double d1 = 19.93;
		      double d2 = 19.96;
		      double d3 = 20.06;
		      double d4 = 20.13;

		      System.out.printf("d1 = %.2f%nd2 = %.2f%nd3 = %.2f%nd4 = %.2f%n%n",
		         d1, d2, d3, d4);

		      System.out.printf("Product of d1 and d2 is %.2f%n", 
		    		  multiply(d1, d2)); 
		      System.out.printf("Product of d1, d2 and d3 is %.2f%n", 
		    		  multiply(d1, d2, d3));
		      System.out.printf("Product of d1, d2, d3 and d4 is %.2f%n", 
		    		  multiply(d1, d2, d3, d4));
	 
	}
	}
 

執行結果：