code: /*
   * Copyright (c) 1994, 2011, 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 java.lang;
  
  /**
   * The abstract class {@code Number} is the superclass of platform
   * classes representing numeric values that are convertible to the
   * primitive types {@code byte}, {@code double}, {@code float}, {@code
   * int}, {@code long}, and {@code short}.
   *
   * The specific semantics of the conversion from the numeric value of
   * a particular {@code Number} implementation to a given primitive
   * type is defined by the {@code Number} implementation in question.
   *
   * For platform classes, the conversion is often analogous to a
   * narrowing primitive conversion or a widening primitive conversion
   * as defining in <cite>The Java&trade; Language Specification</cite>
   * for converting between primitive types.  Therefore, conversions may
   * lose information about the overall magnitude of a numeric value, may
   * lose precision, and may even return a result of a different sign
   * than the input.
   *
   * See the documentation of a given {@code Number} implementation for
   * conversion details.
   *
   * @author      Lee Boynton
   * @author      Arthur van Hoff
   * @jls 5.1.2 Widening Primitive Conversions
   * @jls 5.1.3 Narrowing Primitive Conversions
   * @since   JDK1.0
   */
  public abstract class Number implements java.io.Serializable {
      /**
       * Returns the value of the specified number as an {@code int},
       * which may involve rounding or truncation.
       *
       * @return  the numeric value represented by this object after conversion
       *          to type {@code int}.
       */
      public abstract int intValue();
  
      /**
       * Returns the value of the specified number as a {@code long},
       * which may involve rounding or truncation.
       *
       * @return  the numeric value represented by this object after conversion
       *          to type {@code long}.
       */
      public abstract long longValue();
  
      /**
       * Returns the value of the specified number as a {@code float},
       * which may involve rounding.
       *
       * @return  the numeric value represented by this object after conversion
       *          to type {@code float}.
       */
      public abstract float floatValue();
  
      /**
       * Returns the value of the specified number as a {@code double},
       * which may involve rounding.
       *
       * @return  the numeric value represented by this object after conversion
       *          to type {@code double}.
       */
      public abstract double doubleValue();
  
      /**
       * Returns the value of the specified number as a {@code byte},
       * which may involve rounding or truncation.
       *
       * <p>This implementation returns the result of {@link #intValue} cast
       * to a {@code byte}.
       *
       * @return  the numeric value represented by this object after conversion
       *          to type {@code byte}.
       * @since   JDK1.1
       */
      public byte byteValue() {
          return (byte)intValue();
      }
  
      /**
       * Returns the value of the specified number as a {@code short},
       * which may involve rounding or truncation.
       *
       * <p>This implementation returns the result of {@link #intValue} cast
       * to a {@code short}.
       *
       * @return  the numeric value represented by this object after conversion
       *          to type {@code short}.
       * @since   JDK1.1
       */
      public short shortValue() {
          return (short)intValue();
      }
  
      /** use serialVersionUID from JDK 1.0.2 for interoperability */
      private static final long serialVersionUID = -8742448824652078965L;
  }
  