| <html lang="en"> |
| <head> |
| <title>Binary constants - Using the GNU Compiler Collection (GCC)</title> |
| <meta http-equiv="Content-Type" content="text/html"> |
| <meta name="description" content="Using the GNU Compiler Collection (GCC)"> |
| <meta name="generator" content="makeinfo 4.13"> |
| <link title="Top" rel="start" href="index.html#Top"> |
| <link rel="up" href="C-Extensions.html#C-Extensions" title="C Extensions"> |
| <link rel="prev" href="Thread_002dLocal.html#Thread_002dLocal" title="Thread-Local"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, |
| 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, |
| 2008 Free Software Foundation, Inc. |
| |
| Permission is granted to copy, distribute and/or modify this document |
| under the terms of the GNU Free Documentation License, Version 1.2 or |
| any later version published by the Free Software Foundation; with the |
| Invariant Sections being ``Funding Free Software'', the Front-Cover |
| Texts being (a) (see below), and with the Back-Cover Texts being (b) |
| (see below). A copy of the license is included in the section entitled |
| ``GNU Free Documentation License''. |
| |
| (a) The FSF's Front-Cover Text is: |
| |
| A GNU Manual |
| |
| (b) The FSF's Back-Cover Text is: |
| |
| You have freedom to copy and modify this GNU Manual, like GNU |
| software. Copies published by the Free Software Foundation raise |
| funds for GNU development.--> |
| <meta http-equiv="Content-Style-Type" content="text/css"> |
| <style type="text/css"><!-- |
| pre.display { font-family:inherit } |
| pre.format { font-family:inherit } |
| pre.smalldisplay { font-family:inherit; font-size:smaller } |
| pre.smallformat { font-family:inherit; font-size:smaller } |
| pre.smallexample { font-size:smaller } |
| pre.smalllisp { font-size:smaller } |
| span.sc { font-variant:small-caps } |
| span.roman { font-family:serif; font-weight:normal; } |
| span.sansserif { font-family:sans-serif; font-weight:normal; } |
| --></style> |
| <link rel="stylesheet" type="text/css" href="../cs.css"> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="Binary-constants"></a> |
| <p> |
| Previous: <a rel="previous" accesskey="p" href="Thread_002dLocal.html#Thread_002dLocal">Thread-Local</a>, |
| Up: <a rel="up" accesskey="u" href="C-Extensions.html#C-Extensions">C Extensions</a> |
| <hr> |
| </div> |
| |
| <h3 class="section">6.57 Binary constants using the ‘<samp><span class="samp">0b</span></samp>’ prefix</h3> |
| |
| <p><a name="index-Binary-constants-using-the-_0040samp_007b0b_007d-prefix-3156"></a> |
| Integer constants can be written as binary constants, consisting of a |
| sequence of ‘<samp><span class="samp">0</span></samp>’ and ‘<samp><span class="samp">1</span></samp>’ digits, prefixed by ‘<samp><span class="samp">0b</span></samp>’ or |
| ‘<samp><span class="samp">0B</span></samp>’. This is particularly useful in environments that operate a |
| lot on the bit-level (like microcontrollers). |
| |
| <p>The following statements are identical: |
| |
| <pre class="smallexample"> i = 42; |
| i = 0x2a; |
| i = 052; |
| i = 0b101010; |
| </pre> |
| <p>The type of these constants follows the same rules as for octal or |
| hexadecimal integer constants, so suffixes like ‘<samp><span class="samp">L</span></samp>’ or ‘<samp><span class="samp">UL</span></samp>’ |
| can be applied. |
| |
| </body></html> |
| |