Java printf求和和平均值

Question

这就是我所拥有的：

  double[] miles = new double [10];

  double milesPerWeek = 26.0 / 10;
  double totalMiles = 0;
  double sum = 0;
  double average = 0;

  System.out.println("Week\tMiles");

  for (int i = 0; i < miles.length; i++){

     miles[i] += milesPerWeek;
     totalMiles += miles[i];

     System.out.printf("Week %d\t%.1f%n", i + 1, totalMiles);
  }
  for (int i = 0; i < miles.length; i++)
  {              
     sum = sum + miles[i];
     average = sum / miles.length;
  }
  System.out.printf("The total of miles run is: %.1f%n" + sum + "\n");

  System.out.printf("The average of miles run is: %.1f%n" + average);

这是我和sum和average的问题。 我似乎无法使用print f格式化小数位而没有此错误消息：运行的总里程数为：线程中的异常“main”java.util.MissingFormatArgumentException：格式说明符'％。1f'

你能指点我，因为我需要一个小数位。

Answer 1

您需要将值作为参数传递，而不是将它们连接起来：

System.out.printf("The total of miles run is: %.1f%n\n", sum);

System.out.printf("The average of miles run is: %.1f%n", average);

Answer 2

System.out.println("Blah %.1f\n", sum);

Answer 3

你知道有一个阿哈的那一刻！ 我只是拥有它...加号不会用于形成你的输出......逗号是！ 更正语法：

System.out.printf("The total of miles run is: %.1f%n", sum, "\n");

System.out.printf("The average of miles run is: %.1f%n", average);