我们将看到两个使用数组查找数字平均值的程序。第一个程序查找指定数组元素的平均值。第二个程序获取n（元素数）的值和用户提供的数字，并使用数组查找它们的平均值。
示例 1：使用数组查找数字平均值
public class JavaExample { public static void main(String[] args) { double[] arr = {19, 12.89, 16.5, 200, 13.7}; double total = 0; for(int i=0; i<arr.length; i++){ total = total + arr[i]; } /* arr.length returns the number of elements * present in the array */ double average = total / arr.length; /* This is used for displaying the formatted output * if you give %.4f then the output would have 4 digits * after decimal point. */ System.out.format("The average is: %.3f", average); }}输出：
The average is: 52.418
示例 2：计算用户输入的数字的平均值
在此示例中，我们使用Scanner来获取n的值以及来自用户的所有数字。
import java.util.Scanner;public class JavaExample { public static void main(String[] args) { System.out.println("How many numbers you want to enter?"); Scanner scanner = new Scanner(System.in); int n = scanner.nextInt(); /* Declaring array of n elements, the value * of n is provided by the user */ double[] arr = new double[n]; double total = 0; for(int i=0; i<arr.length; i++){ System.out.print("Enter Element No."+(i+1)+": "); arr[i] = scanner.nextDouble(); } scanner.close(); for(int i=0; i<arr.length; i++){ total = total + arr[i]; } double average = total / arr.length; System.out.format("The average is: %.3f", average); }}
输出：
How many numbers you want to enter?5Enter Element No.1: 12.7Enter Element No.2: 18.9Enter Element No.3: 20Enter Element No.4: 13.923Enter Element No.5: 15.6The average is: 16.225
