Checks if x is a power-of-two number. - Java java.lang

Java examples for java.lang:Math Operation

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Description

Checks if x is a power-of-two number.

Demo Code

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1//from www.  java2  s.  c om
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Parallel Colt.
 *
 * The Initial Developer of the Original Code is
 * Piotr Wendykier, Emory University.
 * Portions created by the Initial Developer are Copyright (C) 2007-2009
 * the Initial Developer. All Rights Reserved.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * decision by deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this file under
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 *
 * ***** END LICENSE BLOCK ***** */
//package com.java2s;

public class Main {
    public static void main(String[] argv) throws Exception {
        int x = 2;
        System.out.println(isPowerOf2(x));
    }

    /**
     * Checks if x is a power-of-two number.
     * 
     * @param x
     * @return true if x is a power-of-two number
     */
    public static boolean isPowerOf2(int x) {
        if (x <= 0)
            return false;
        else
            return (x & (x - 1)) == 0;
    }
}

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