java - 我如何从java中的整数中获取 double 值？

Question

这个问题已经有答案了:

Integer division: How do you produce a double? (11 个回答)

已关闭 10 年前。

所以我很难弄清楚如何正确地得出这些值。所有的数学都是正确的，但它只表述了整数。例如，当我输入数字 87、42 和 94 时，平均值应为 74.3 重复。但对我来说它只得到 74.0。最低分数的平均值也是如此。

Scanner keyboard = new Scanner(System.in);

int a;
int b;
int c;
double grade;
double avg;
double avg2 = 0;

System.out.print("Enter score number 1: ");
a = keyboard.nextInt();
System.out.print("Enter score number 2: ");
b = keyboard.nextInt();
System.out.print("Enter score number 3: ");
c = keyboard.nextInt();

avg = ((a + b + c) / 3);


System.out.println("The average is: " + avg);

if (a < b && a < c)
{
    System.out.println("The lowest score was: " + a);
    System.out.println("The average without the lowest score is: " + ((b + c) / 2));
    avg2 = ((b + c) / 2);
}


if (b < a && b < c)
{
    System.out.println("The lowest score was: " + b);
    System.out.println("The average without the lowest score is: " + ((a + c) / 2));
    avg2 = ((a + c) / 2);
}


if (c < a && c < b)
{
    System.out.println("The lowest score was: " + c);
    System.out.println("The average without the lowest score is: " + ((a + b) /2));
    avg2 = ((a + b) / 2);
}

Answer 1

您必须将 avg 表达式的分子中的总和转换为 double 或在分母中使用 double :

平均 = ((双)(a + b + c)/3);

或

平均值 = ((a + b + c)/3.0);