Here you can find the source of toDigit(int c)
private static int toDigit(int c)
//package com.java2s; /* Copyright (C) 2013-2014 Ian Teune <ian.teune@gmail.com> * //w w w . j a v a2 s . c om * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ public class Main { private static int toDigit(int c) { if (c > '9') { if (c > 'F') { if (c >= 'a' && c <= 'f') { return c - 'a' + 10; } } else if (c >= 'A') { return c - 'A' + 10; } } else if (c >= '0') { return c - '0'; } throw new IllegalArgumentException(); } }