Java example source code file (DoubleConsts.java)

This example Java source code file (DoubleConsts.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

doubleconsts, exp_bias, exp_bit_mask, max_exponent, max_value, min_exponent, min_normal, min_value, nan, negative_infinity, positive_infinity, sign_bit_mask, signif_bit_mask, significand_width

The DoubleConsts.java Java example source code

/*
 * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package sun.misc;

/**
 * This class contains additional constants documenting limits of the
 * <code>double type.
 *
 * @author Joseph D. Darcy
 */

public class DoubleConsts {
    /**
     * Don't let anyone instantiate this class.
     */
    private DoubleConsts() {}

    public static final double POSITIVE_INFINITY = java.lang.Double.POSITIVE_INFINITY;
    public static final double NEGATIVE_INFINITY = java.lang.Double.NEGATIVE_INFINITY;
    public static final double NaN = java.lang.Double.NaN;
    public static final double MAX_VALUE = java.lang.Double.MAX_VALUE;
    public static final double MIN_VALUE = java.lang.Double.MIN_VALUE;

    /**
     * A constant holding the smallest positive normal value of type
     * <code>double, 2-1022.  It is equal to the
     * value returned by
     * <code>Double.longBitsToDouble(0x0010000000000000L).
     *
     * @since 1.5
     */
    public static final double  MIN_NORMAL      = 2.2250738585072014E-308;


    /**
     * The number of logical bits in the significand of a
     * <code>double number, including the implicit bit.
     */
    public static final int SIGNIFICAND_WIDTH   = 53;

    /**
     * Maximum exponent a finite <code>double number may have.
     * It is equal to the value returned by
     * <code>Math.ilogb(Double.MAX_VALUE).
     */
    public static final int     MAX_EXPONENT    = 1023;

    /**
     * Minimum exponent a normalized <code>double number may
     * have.  It is equal to the value returned by
     * <code>Math.ilogb(Double.MIN_NORMAL).
     */
    public static final int     MIN_EXPONENT    = -1022;

    /**
     * The exponent the smallest positive <code>double
     * subnormal value would have if it could be normalized.  It is
     * equal to the value returned by
     * <code>FpUtils.ilogb(Double.MIN_VALUE).
     */
    public static final int     MIN_SUB_EXPONENT = MIN_EXPONENT -
                                                   (SIGNIFICAND_WIDTH - 1);

    /**
     * Bias used in representing a <code>double exponent.
     */
    public static final int     EXP_BIAS        = 1023;

    /**
     * Bit mask to isolate the sign bit of a <code>double.
     */
    public static final long    SIGN_BIT_MASK   = 0x8000000000000000L;

    /**
     * Bit mask to isolate the exponent field of a
     * <code>double.
     */
    public static final long    EXP_BIT_MASK    = 0x7FF0000000000000L;

    /**
     * Bit mask to isolate the significand field of a
     * <code>double.
     */
    public static final long    SIGNIF_BIT_MASK = 0x000FFFFFFFFFFFFFL;

    static {
        // verify bit masks cover all bit positions and that the bit
        // masks are non-overlapping
        assert(((SIGN_BIT_MASK | EXP_BIT_MASK | SIGNIF_BIT_MASK) == ~0L) &&
               (((SIGN_BIT_MASK & EXP_BIT_MASK) == 0L) &&
                ((SIGN_BIT_MASK & SIGNIF_BIT_MASK) == 0L) &&
                ((EXP_BIT_MASK & SIGNIF_BIT_MASK) == 0L)));
    }
}