Java如何计算3个保龄球得分的平均值

Question

我正在编写一个程序来计算和显示用户输入的每个保龄球手的平均保龄球得分。 我在计算 3 个分数的平均值时遇到问题，现在我认为它正在计算分数的总和。 我如何使它计算分数的平均值

public static void main (String [] args)
{



//local constants


  //local variables
    String bowler = "";
    int total = 0;
    int average = 0;
    int score1 = 0;
    int score2 = 0;
    int score3 = 0;

  /********************   Start main method  *****************/

  //Enter in the name of the first bowler
  System.out.print(setLeft(40," Input First Bowler or stop to Quit: "));
  bowler = Keyboard.readString();

  //Enter While loop if input isn't q
  while(!bowler.equals("stop"))
  {

      System.out.print(setLeft(40," 1st Bowling Score:"));
      score1 = Keyboard.readInt();
      System.out.print(setLeft(40," 2nd Bowling Score:"));
      score2 = Keyboard.readInt();
      System.out.print(setLeft(40," 3rd Bowling Score:"));
      score3 = Keyboard.readInt();
      if(score1 >= 0 && score1 <= 300 && score2 >= 0 && score2 <= 300 && score3 >= 0 && score3 <= 300)
      {
          total += score1;
          total += score2;
          total += score3;
          System.out.println(setLeft(41,"Total: ")+ total);
          average = score1 + score2 + score3 / 3;
          System.out.println(setLeft(41,"Average: ") + average);


      }
      else
      {
          System.out.println(setLeft(40,"Error"));

      }

Answer 1

Java 的数学运算符遵循标准的数学优先级，所以它是

   int average = score1 + score2 + (score3 / 3);

但是，您的意图很可能

   int average = (score1 + score2 + score3) / 3;

最后，您很可能想在double （或float ）算术中进行此计算，否则将四舍五入

double average = (double)(score1 + score2 + score3) / 3;

Answer 2

除法 ( / ) 运算符的优先级高于加法运算符 ( + )，因此您需要在除法之前将总和用括号括起来：

average = (score1 + score2 + score3) / 3;
// Here --^------------------------^