如何使用Java从输入计算平均值？

Question

I need a program that should add x numbers. The numbers should come from user input so I need some sort of loop. I have gotten as far as shown below, but I'm stuck since I have no idea how to add a new number without deleting the previous?

System.out.println("How many numbers to use?");
int number = keyboard.nextInt();

for (int i = 0; i<number ; i++) {
    System.out.println("whats the  number");
    double first = keyboard.nextDouble();
}

Answer 1

If all you need is the average, you don't need to keep all the numbers you get from user input. Just keep one variable that holds their sum.

define the sum variable outside the loop (initialized to 0), and add to it each number you get from user input.

Answer 2

int number = keyboard.nextInt();
double sum = 0;

for (int i = 0; i<number ; i++) 
{
    System.out.println("whats the  number");
    sum += keyboard.nextDouble();
}

double average = sum / number;

Answer 3

public class Average {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    double sum = 0;
    int num;
    System.out.println("enter how many num");
    num = sc.nextInt();
    System.out.println("please enter " + num + " numbers");
    for (int i = 0; i < num; i++) {
        sum += sc.nextDouble();
    }
    double avg = sum / num;
    System.out.println("Average of " + num + " numbers is:" + avg);
}

}