Number e

NumberE.java

package numbere;

public class NumberE {

    public static void main(String[] args) {

        double e = 2, el = 1, accuracy = Math.pow(10, -16);
        long factorial = 1, i = 1;

        long startTime = System.nanoTime();

        while (el > accuracy) {
            e += (el = 1.0 / (factorial *= ++i));
        }

        long endTime = System.nanoTime();

        System.out.println("e = " + e + " in " + (endTime - startTime) + " ns ("+ (i - 1) +" iterations)");
    }
}