java.lang.Number Maven / Gradle / Ivy
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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 The Java™ Language Specification
* 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.
*
* 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.
*
*
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;
}