java - Java-仅显示两个小数点？

Question

这个问题已经有了答案：
How to display an output of float data with 2 decimal places in Java?
16个答案
所以我的程序也做了我想做的一切，除了当随机数为temps生成时，只显示小数点后2位（12.00）。它现在正在做的是（12.1234567897654）。
我是一个Java初学者，这是我自己完成的第一个程序，所以如果答案很明显，请不要吝啬：
我试过printf和%.2f，但我没法用

public class ArrayOfTemperatures
{
  public static void main(String[] args)
   {

  double [] temp = new double [7];


  double random = Math.random() * 100 + 1;

  temp[0] = Math.random() * 100 + 1;

     //Calculating average          
     int sum = 0;
     for (int i = 0; i < temp.length; i++) {
        temp[i] =  Math.random() * 100 + 1;
        sum += temp[i];
      }

     //average being stated
     double average = (double) sum / temp.length;
     System.out.println("The average temperature is " + average);

    //Temperatures
    for (int i = 0; i < temp.length; i++) {
     temp[i] =  Math.random() * 100 + 1;
     System.out.print("Temperature " + (i + 1) + " is: " + temp[i]);
        if (temp[i] > average){
           System.out.println(" and is above average.");
        }
        else {
           System.out.println(" and is below average.");
        }


      }          

   }         
}

输出示例如下：

The average temperature is 42.714285714285715
Temperature 1 is: 14.71803486458223 and is below average.
Temperature 2 is: 33.10321474550992 and is below average. 
Temperature 3 is: 18.661262675746727 and is below average. 
Temperature 4 is: 82.12893152205741 and is above average. 
Temperature 5 is: 90.97086140892438 and is above average. 
Temperature 6 is: 19.609064446916477 and is below average. 
Temperature 7 is: 75.47742502105827 and is above average. 

Answer 1

您可以使用format函数。基本上，它和printf一样。尝试

System.out.println(String.format("Temperature %d is: %.2f", i + 1, temp[i]));