< prev index next >

src/java.base/share/classes/java/lang/Number.java

Print this page

  7  * published by the Free Software Foundation.  Oracle designates this
  8  * particular file as subject to the "Classpath" exception as provided
  9  * by Oracle in the LICENSE file that accompanied this code.
 10  *
 11  * This code is distributed in the hope that it will be useful, but WITHOUT
 12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 14  * version 2 for more details (a copy is included in the LICENSE file that
 15  * accompanied this code).
 16  *
 17  * You should have received a copy of the GNU General Public License version
 18  * 2 along with this work; if not, write to the Free Software Foundation,
 19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 20  *
 21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 22  * or visit www.oracle.com if you need additional information or have any
 23  * questions.
 24  */
 25 
 26 package java.lang;
 27 
 28 /**
 29  * The abstract class {@code Number} is the superclass of platform
 30  * classes representing numeric values that are convertible to the
 31  * primitive types {@code byte}, {@code double}, {@code float}, {@code
 32  * int}, {@code long}, and {@code short}.
 33  *
 34  * The specific semantics of the conversion from the numeric value of
 35  * a particular {@code Number} implementation to a given primitive
 36  * type is defined by the {@code Number} implementation in question.
 37  *
 38  * For platform classes, the conversion is often analogous to a
 39  * narrowing primitive conversion or a widening primitive conversion
 40  * as defined in <cite>The Java Language Specification</cite>
 41  * for converting between primitive types.  Therefore, conversions may
 42  * lose information about the overall magnitude of a numeric value, may
 43  * lose precision, and may even return a result of a different sign
 44  * than the input.
 45  *
 46  * See the documentation of a given {@code Number} implementation for
 47  * conversion details.
 48  *
 49  * @author      Lee Boynton
 50  * @author      Arthur van Hoff
 51  * @jls 5.1.2 Widening Primitive Conversion
 52  * @jls 5.1.3 Narrowing Primitive Conversion
 53  * @since   1.0
 54  */

 55 public abstract class Number implements java.io.Serializable {
 56     /**
 57      * Constructor for subclasses to call.
 58      */
 59     public Number() {super();}
 60 
 61     /**
 62      * Returns the value of the specified number as an {@code int}.
 63      *
 64      * @return  the numeric value represented by this object after conversion
 65      *          to type {@code int}.
 66      */
 67     public abstract int intValue();
 68 
 69     /**
 70      * Returns the value of the specified number as a {@code long}.
 71      *
 72      * @return  the numeric value represented by this object after conversion
 73      *          to type {@code long}.
 74      */

  7  * published by the Free Software Foundation.  Oracle designates this
  8  * particular file as subject to the "Classpath" exception as provided
  9  * by Oracle in the LICENSE file that accompanied this code.
 10  *
 11  * This code is distributed in the hope that it will be useful, but WITHOUT
 12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 14  * version 2 for more details (a copy is included in the LICENSE file that
 15  * accompanied this code).
 16  *
 17  * You should have received a copy of the GNU General Public License version
 18  * 2 along with this work; if not, write to the Free Software Foundation,
 19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 20  *
 21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 22  * or visit www.oracle.com if you need additional information or have any
 23  * questions.
 24  */
 25 
 26 package java.lang;

 27 /**
 28  * The abstract class {@code Number} is the superclass of platform
 29  * classes representing numeric values that are convertible to the
 30  * primitive types {@code byte}, {@code double}, {@code float}, {@code
 31  * int}, {@code long}, and {@code short}.
 32  *
 33  * The specific semantics of the conversion from the numeric value of
 34  * a particular {@code Number} implementation to a given primitive
 35  * type is defined by the {@code Number} implementation in question.
 36  *
 37  * For platform classes, the conversion is often analogous to a
 38  * narrowing primitive conversion or a widening primitive conversion
 39  * as defined in <cite>The Java Language Specification</cite>
 40  * for converting between primitive types.  Therefore, conversions may
 41  * lose information about the overall magnitude of a numeric value, may
 42  * lose precision, and may even return a result of a different sign
 43  * than the input.
 44  *
 45  * See the documentation of a given {@code Number} implementation for
 46  * conversion details.
 47  *
 48  * @author      Lee Boynton
 49  * @author      Arthur van Hoff
 50  * @jls 5.1.2 Widening Primitive Conversion
 51  * @jls 5.1.3 Narrowing Primitive Conversion
 52  * @since   1.0
 53  */
 54 @jdk.internal.MigratedValueClass
 55 public abstract class Number implements java.io.Serializable {
 56     /**
 57      * Constructor for subclasses to call.
 58      */
 59     public Number() {super();}
 60 
 61     /**
 62      * Returns the value of the specified number as an {@code int}.
 63      *
 64      * @return  the numeric value represented by this object after conversion
 65      *          to type {@code int}.
 66      */
 67     public abstract int intValue();
 68 
 69     /**
 70      * Returns the value of the specified number as a {@code long}.
 71      *
 72      * @return  the numeric value represented by this object after conversion
 73      *          to type {@code long}.
 74      */
< prev index next >