新・明解Java入門　演習6-8

En06_08.java

import java.util.Scanner;

public class En06_08 {
	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);

		int youso;
		do {
			System.out.print("要素数：");
			youso = stdIn.nextInt();
		} while (youso < 1);

		// 配列を作成
		double[] doubles = new double[youso];

		// for文で値を配列へ代入する
		for (int i = 0; i < doubles.length; i++) {
			System.out.printf("要素a[%d]：", i);
			doubles[i] = stdIn.nextDouble();
		}
		System.out.println();

		// 合計を計算
		double sum = 0;
		for (double i : doubles) {
			sum += i;
		}

		System.out.printf("合計：%.1f\n", sum);
		System.out.printf("平均：%.1f\n", (sum / youso));
	}
}