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 * 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
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 */

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;
}
