Here you can find the source of random(int theRange)
public static int random(int theRange)
//package com.java2s; /*/* w w w .j ava2 s . c o m*/ * Werkzeug * * Copyright (C) 2012 Patrick Kochlik + Dennis Paul * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * {@link http://www.gnu.org/licenses/lgpl.html} * */ public class Main { public static int random(int theRange) { double myRandomNumber = Math.random() * (double) (theRange + 1); return (int) myRandomNumber; } public static int random(int theStart, int theEnd) { int myRandomNumber = (int) (Math.random() * (Math.abs(theStart) + Math.abs(theEnd) + 2) - (Math.abs(theStart) + 1)); return Math.min(theEnd, Math.max(myRandomNumber, theStart)); } public static float random(float theStart, float theEnd) { float myRandomNumber = (float) (Math.random() * (Math.abs(theStart) + Math.abs(theEnd)) - Math.abs(theStart)); return Math.min(theEnd, Math.max(myRandomNumber, theStart)); } }