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.. highlight:: cpp
.. _lang-long:
long
====
Description
-----------
The ``long`` data type stores extended size integer values. You can
use a ``long`` when your values are too large to fit into an :ref:`int
<lang-int>`. A ``long`` occupies 8 bytes of memory. This yields a
range of approximately -9.2×10^18 to 9.2×10^18 (that's 9.2 billion
billion, or about 92 million times the number of stars in the Milky
Way galaxy). The exact range of a ``long`` on the Maple is from
-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807, or -2^63 to
(2^63-1). A ``long`` it is subject to the same :ref:`overflow issues
<lang-variables-rollover>` as any numeric data type.
Here's an example of declaring a long (see :ref:`integer constants
<lang-constants-u-l>` for an explanation of the "L" at the end of the
number)::
// Speed of light in nanometers per second (approximate).
long c = 299792458000000000L;
The general syntax for declaring an ``long`` variable named ``var``,
then giving it value ``val``, looks like::
long var = val;
This is identical to the ``int`` syntax, with ``long`` replacing
``int``.
Note that ``long`` values will still :ref:`overflow
<lang-int-overflow>`, just like ``int`` values, but their much
larger range makes this less likely to happen.
The downside to using a ``long`` instead of an ``int`` (besides the
extra storage) is that :ref:`arithmetic <lang-arithmetic>` operations
on ``long``\ s will take slightly longer than on ``int``\ s.
See Also
--------
- :ref:`char <lang-char>`
- :ref:`unsigned char <lang-unsignedchar>`
- :ref:`int <lang-int>`
- :ref:`unsigned int <lang-unsignedint>`
- :ref:`unsigned long <lang-unsignedlong>`
- :ref:`Integer Constants <lang-constants-integers>`
- :ref:`Variables <lang-variables>`
.. include:: cc-attribution.txt
|
