Determines if nNum is a power of 2. - Java java.lang

Java examples for java.lang:Math Calculation

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Description

Determines if nNum is a power of 2.

Demo Code

/*******************************************************************************
 * Copyright (c) 2011 Matthias-M. Christen, University of Basel, Switzerland.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * // w  w w. j  a  va 2 s .c  o  m
 * Contributors:
 *     Matthias-M. Christen, University of Basel, Switzerland - initial API and implementation
 ******************************************************************************/
//package com.java2s;

public class Main {
    /**
     * Determines if <var>nNum</var> is a power of 2.
     * 
     * @param nNum
     *            The integer to test
     * @return <code>true</code> iff <var>nNum</var> is a power of 2.
     */
    public static boolean isPowerOfTwo(int nNum) {
        /*
         for (int i = 1; i <= nNum; i <<= 1)
            if (nNum == i)
               return true;
         return false;
         */

        return nNum > 0 && ((nNum & (nNum - 1)) == 0);
    }
}

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