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<html><title>Programming Ruby: The Pragmatic Programmer's Guide</title><head><meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"><STYLE TYPE="text/css"><!--
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</STYLE><table bgcolor="#a03030" cellpadding="3" border="0" cellspacing="0"><tr><td colspan="3"><table bgcolor="#902020" cellpadding="20"><tr><td><h1 class="header">Programming Ruby</h1><h3 class="subheader">The Pragmatic Programmer's Guide</h3></td></tr></table></td></tr><tr><td width="33%" align="left"><a class="subheader" href="ref_c_struct__tms.html">Previous <</a></td><td width="33%" align="center" valign="middle"><a class="subheader" href="builtins.html">Contents ^</a><br></td><td width="33%" align="right"><a class="subheader" href="ref_c_thread.html">Next ></a><br></td></tr></table></head><body bgcolor="white">
<!--
Copyright (c) 2001 by Addison Wesley Longman. This
material may be distributed only subject to the terms and
conditions set forth in the Open Publication License, v1.0 or
later (the latest version is presently available at
http://www.opencontent.org/openpub/).
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<table><tr><td height="20"><img src="dot.gif" width="1" height="20"></td></tr></table><table border="0" width="100%" bgcolor="660066" cellpadding="10"><tr><td valign="center"><font color="white" size="7">class Symbol</font></td><td><table border="0"><tr><td><font color="white">
Parent:
</font></td><td><font color="white">Object</font></td></tr><tr><td><font color="white">
Version:
</font></td><td><font color="white">
1.6
</font></td></tr></table></td></tr></table><p></p><H3>Index:</H3><a href="#id2name"><i>id2name</i></a> <a href="#inspect"><i>inspect</i></a> <a href="#to_i"><i>to_i</i></a> <a href="#to_s"><i>to_s</i></a> <p></p><hr>
<P></P>
A <code>Symbol</code> object represents a Ruby name and is generated
automatically using the <code>:name</code> literal syntax. The same <code>Symbol</code>
object will be created for a given name string for the duration of a
program's execution, regardless of the context or meaning of that
name. Thus if <code>Fred</code> is a constant in one context, a method in
another, and a class in a third, the <code>Symbol</code> <code>:Fred</code> will be
the same object in all three contexts.
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3" width="500">
<tr>
<td colspan="3" valign="top"><code>module One</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code> class Fred</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code> end</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code> $f1 = :Fred</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code>end</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code>module Two</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code> Fred = 1</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code> $f2 = :Fred</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code>end</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code>def Fred()</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code>end</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code>$f3 = :Fred</code></td>
</tr>
<tr>
<td valign="top"><code>$f1.id</code></td>
<td valign="top"></td>
<td valign="top"><code>2299150</code></td>
</tr>
<tr>
<td valign="top"><code>$f2.id</code></td>
<td valign="top"></td>
<td valign="top"><code>2299150</code></td>
</tr>
<tr>
<td valign="top"><code>$f3.id</code></td>
<td valign="top"></td>
<td valign="top"><code>2299150</code></td>
</tr>
</table>
<P></P>
<P></P>
<table border="0" width="100%" cellpadding="10"><tr><td valign="center" colspan="2" bgcolor="990066"><font color="white" size="6">instance methods
</font></td></tr><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="id2name"><b>id2name</b></a></font></td><td bgcolor="#ffaaaa">
<i>sym</i>.id2name -> <i>aString</i>
</td></tr><td></td><td>
<P></P>
Returns the name corresponding to <i>sym</i>.
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3" width="500">
<tr>
<td valign="top"><code>:fred.id2name</code></td>
<td valign="top"></td>
<td valign="top"><code>"fred"</code></td>
</tr>
</table>
<P></P>
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="inspect"><b>inspect</b></a></font></td><td bgcolor="#ffaaaa">
<i>sym</i>.inspect -> <i>aString</i>
</td></tr><td></td><td>
<P></P>
Returns the representation of <i>sym</i> as a symbol literal.
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3" width="500">
<tr>
<td valign="top"><code>:fred.inspect</code></td>
<td valign="top"></td>
<td valign="top"><code>":fred"</code></td>
</tr>
</table>
<P></P>
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="to_i"><b>to_i</b></a></font></td><td bgcolor="#ffaaaa">
<i>sym</i>.to_i -> <i>aFixnum</i>
</td></tr><td></td><td>
<P></P>
Returns an integer that is unique for each symbol within a
particular execution of a program.
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="to_s"><b>to_s</b></a></font></td><td bgcolor="#ffaaaa">
<i>sym</i>.to_s -> <i>aString</i>
</td></tr><td></td><td>
<P></P>
Synonym for <a href="ref_c_symbol.html#id2name"><code>Symbol#id2name</code></a>.
<P></P>
</td></table>
<P></P>
<p></p><hr><table bgcolor="#a03030" cellpadding="10" border="0" cellspacing="0"><tr><td width="33%" align="left"><a class="subheader" href="ref_c_struct__tms.html">Previous <</a></td><td width="33%" align="center" valign="middle"><a class="subheader" href="builtins.html">Contents ^</a><br></td><td width="33%" align="right"><a class="subheader" href="ref_c_thread.html">Next ></a><br></td></tr></table><p></p><font size="-1">Extracted from the book "Programming Ruby -
The Pragmatic Programmer's Guide"</font><br><font size="-3">
Copyright
©
2000 Addison Wesley Longman, Inc. Released under the terms of the
<a href="http://www.opencontent.org/openpub/">Open Publication License</a> V1.0.
<br>
This reference is available for
<a href="http://www.pragmaticprogrammer.com/ruby/downloads/book.html">download</a>.
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