package questions.section4;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
public class S403StreamInsteadOfFor {
public S403StreamInsteadOfFor() {
processStatistics();
}
private void processStatistics() {
// 乱数のリストを作成
Random random = new Random();
List<Double> numbers = new ArrayList<>();
for (int i = 0; i < 100; i++) {
numbers.add(random.nextDouble());
}
// 平均を算出
double ave = 0.0;
for (Double x : numbers) {
ave += x;
}
ave /= numbers.size();
// 分散を算出
double variance = 0.0;
for (Double x : numbers) {
variance += (x - ave) * (x - ave);
}
variance /= numbers.size();
System.out.println("Average: " + ave);
System.out.println("Diverse: " + variance);
}
public static void main(String[] args) {
new S403StreamInsteadOfFor();
}
}