Here you can find the source of pow10(int n)
public static double pow10(int n)
//package com.java2s; // This software is licensed under the GNU General Public License, public class Main { public static double pow10(int n) { if (n == 0) return 1; else if (n > 0) { double d = 1; for (int i = 0; i < n; i++) d = d * 10.;//w w w. jav a 2 s. co m return d; } else { double d = 1; for (int i = 0; i > n; i--) d = d / 10.; return d; } } }