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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_nilclass.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_object.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 Numeric</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="#_pl_at"><i>+@</i></a> <a href="#_mi_mi_at"><i>--@</i></a> <a href="#abs"><i>abs</i></a> <a href="#coerce"><i>coerce</i></a> <a href="#divmod"><i>divmod</i></a> <a href="#eql_qm"><i>eql?</i></a> <a href="#integer_qm"><i>integer?</i></a> <a href="#modulo"><i>modulo</i></a> <a href="#nonzero_qm"><i>nonzero?</i></a> <a href="#remainder"><i>remainder</i></a> <a href="#zero_qm"><i>zero?</i></a> <p></p><hr>
<P></P>
<br><font size="-1">Subclasses: Float, Integer</font><p></p>
<P></P>
Numeric is the fundamental base type for the concrete number classes
<code>Float</code>, <code>Fixnum</code>, and <code>Bignum</code>.
<table border="0" width="100%" cellpadding="10"><tr><td valign="center" colspan="2" bgcolor="990066"><font color="white" size="6">
mixins
</font></td></tr>
<tr><td>Comparable:
</td><td>
<, <=, ==, >=, >, between?</td></tr>
</table>
<P></P>
<table border="2" width="500" bgcolor="#ffe0e0"><tr><td>
<b>Difference between modulo and
remainder. The modulo operator
(``%'') always has the sign of the divisor, whereas
<code>remainder</code> has the sign of the dividend.</b>
<center>
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3">
<tr bgcolor="#ff9999">
<td valign="top"><b>a</b></td>
<td valign="top"><b>b</b></td>
<td colspan="2" valign="top"><b>a.divmod(b)</b></td>
<td colspan="1" valign="top"><b>a / b</b></td>
<td colspan="1" valign="top"><b>a.modulo(b)</b></td>
<td colspan="1" valign="top"><b>a.remainder(b)</b></td>
</tr>
<tr>
<td valign="top">13</td>
<td valign="top">4</td>
<td valign="top">3,</td>
<td valign="top">1</td>
<td valign="top">3</td>
<td valign="top">1</td>
<td valign="top">1</td>
</tr>
<tr>
<td valign="top">13</td>
<td valign="top">-4</td>
<td valign="top">-4,</td>
<td valign="top">-3</td>
<td valign="top">-4</td>
<td valign="top">-3</td>
<td valign="top">1</td>
</tr>
<tr>
<td valign="top">-13</td>
<td valign="top">4</td>
<td valign="top">-4,</td>
<td valign="top">3</td>
<td valign="top">-4</td>
<td valign="top">3</td>
<td valign="top">-1</td>
</tr>
<tr>
<td valign="top">-13</td>
<td valign="top">-4</td>
<td valign="top">3,</td>
<td valign="top">-1</td>
<td valign="top">3</td>
<td valign="top">-1</td>
<td valign="top">-1</td>
</tr>
<tr>
<td valign="top">11.5</td>
<td valign="top">4</td>
<td valign="top">2.0,</td>
<td valign="top">3.5</td>
<td valign="top">2.875</td>
<td valign="top">3.5</td>
<td valign="top">3.5</td>
</tr>
<tr>
<td valign="top">11.5</td>
<td valign="top">-4</td>
<td valign="top">-3.0,</td>
<td valign="top">-0.5</td>
<td valign="top">-2.875</td>
<td valign="top">-0.5</td>
<td valign="top">3.5</td>
</tr>
<tr>
<td valign="top">-11.5</td>
<td valign="top">4</td>
<td valign="top">-3.0,</td>
<td valign="top">0.5</td>
<td valign="top">-2.875</td>
<td valign="top">0.5</td>
<td valign="top">-3.5</td>
</tr>
<tr>
<td valign="top">-11.5</td>
<td valign="top">-4</td>
<td valign="top">2.0,</td>
<td valign="top">-3.5</td>
<td valign="top">2.875</td>
<td valign="top">-3.5</td>
<td valign="top">-3.5</td>
</tr>
<tr><td colspan="9" bgcolor="#ff9999" height="2"><img src="dot.gif" width="1" height="1"></td></tr></table>
<P></P>
</center>
</td></tr></table><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="_pl_at"><b>+@</b></a></font></td><td bgcolor="#ffaaaa">
+<i>num</i> -> <i>num</i>
</td></tr><td></td><td>
<P></P>
Unary Plus---Returns the receiver's value.
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="_mi_mi_at"><b>--@</b></a></font></td><td bgcolor="#ffaaaa">
--<i>num</i> -> <i>aNumeric</i>
</td></tr><td></td><td>
<P></P>
Unary Minus---Returns the receiver's value, negated.
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="abs"><b>abs</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.abs -> <i>aNumeric</i>
</td></tr><td></td><td>
<P></P>
Returns the absolute value of <i>num</i>.
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3" width="500">
<tr>
<td valign="top"><code>12.abs</code></td>
<td valign="top"></td>
<td valign="top"><code>12</code></td>
</tr>
<tr>
<td valign="top"><code>(-34.56).abs</code></td>
<td valign="top"></td>
<td valign="top"><code>34.56</code></td>
</tr>
<tr>
<td valign="top"><code>-34.56.abs</code></td>
<td valign="top"></td>
<td valign="top"><code>34.56</code></td>
</tr>
</table>
<P></P>
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="coerce"><b>coerce</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.coerce( <i>aNumeric</i> )
-> <i>anArray</i>
</td></tr><td></td><td>
<P></P>
If <i>aNumeric</i> is the same type as <i>num</i>, returns an array
containing <i>aNumeric</i> and <i>num</i>. Otherwise, returns an
array with both <i>aNumeric</i> and <i>num</i> represented as
<code>Float</code> objects.
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3" width="500">
<tr>
<td valign="top"><code>1.coerce(2.5)</code></td>
<td valign="top"></td>
<td valign="top"><code>[2.5, 1.0]</code></td>
</tr>
<tr>
<td valign="top"><code>1.2.coerce(3)</code></td>
<td valign="top"></td>
<td valign="top"><code>[3.0, 1.2]</code></td>
</tr>
<tr>
<td valign="top"><code>1.coerce(2)</code></td>
<td valign="top"></td>
<td valign="top"><code>[2, 1]</code></td>
</tr>
</table>
<P></P>
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="divmod"><b>divmod</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.divmod( <i>aNumeric</i> )
-> <i>anArray</i>
</td></tr><td></td><td>
<P></P>
Returns an array containing the quotient and modulus obtained by
dividing <i>num</i> by <i>aNumeric</i>.
If <code>q, r = x.divmod(y)</code>,
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3">
<tr>
<td valign="top">q</td>
<td valign="top">=</td>
<td valign="top">floor(float(x) / float(y))</td>
</tr>
<tr>
<td valign="top">x</td>
<td valign="top">=</td>
<td valign="top">q * y + r</td>
</tr>
</table>
<P></P>
The quotient is rounded toward -infinity. See Table
22.6 on page 355.
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3" width="500">
<tr>
<td valign="top"><code>11.divmod(3)</code></td>
<td valign="top"></td>
<td valign="top"><code>[3, 2]</code></td>
</tr>
<tr>
<td valign="top"><code>11.divmod(-3)</code></td>
<td valign="top"></td>
<td valign="top"><code>[-4, -1]</code></td>
</tr>
<tr>
<td valign="top"><code>11.divmod(3.5)</code></td>
<td valign="top"></td>
<td valign="top"><code>[3.0, 0.5]</code></td>
</tr>
<tr>
<td valign="top"><code>(-11).divmod(3.5)</code></td>
<td valign="top"></td>
<td valign="top"><code>[-4.0, 3.0]</code></td>
</tr>
<tr>
<td valign="top"><code>(11.5).divmod(3.5)</code></td>
<td valign="top"></td>
<td valign="top"><code>[3.0, 1.0]</code></td>
</tr>
</table>
<P></P>
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="eql_qm"><b>eql?</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.eql?( <i>aNumeric</i> )
-> <code>true</code> or <code>false</code>
</td></tr><td></td><td>
<P></P>
Returns <code>true</code> if <i>num</i> and <i>aNumeric</i> are the same
type and have equal values.
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3" width="500">
<tr>
<td valign="top"><code>1 == 1.0</code></td>
<td valign="top"></td>
<td valign="top"><code>true</code></td>
</tr>
<tr>
<td valign="top"><code>1.eql?(1.0)</code></td>
<td valign="top"></td>
<td valign="top"><code>false</code></td>
</tr>
<tr>
<td valign="top"><code>(1.0).eql?(1.0)</code></td>
<td valign="top"></td>
<td valign="top"><code>true</code></td>
</tr>
</table>
<P></P>
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="integer_qm"><b>integer?</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.integer? -> <code>true</code> or <code>false</code>
</td></tr><td></td><td>
<P></P>
Returns <code>true</code> if <i>num</i> is an <code>Integer</code> (including
<code>Fixnum</code> and <code>Bignum</code>).
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="modulo"><b>modulo</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.modulo( <i>aNumeric</i> )
-> <i>aNumeric</i>
</td></tr><td></td><td>
<P></P>
Equivalent to <i>num</i>.<code>divmod(</code><i>aNumeric</i><code>)[1]</code>.
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="nonzero_qm"><b>nonzero?</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.nonzero?
-> <i>num</i> or <code>nil</code>
</td></tr><td></td><td>
<P></P>
Returns <i>num</i> if <i>num</i> is not zero, <code>nil</code> otherwise. This
behavior is useful when chaining comparisons:
<P></P>
<table bgcolor="#fff0f0" cellspacing="0" border="0" cellpadding="3" width="500">
<tr>
<td colspan="3" valign="top"><code>a = %w( z Bb bB bb BB a aA Aa AA A )</code></td>
</tr>
<tr>
<td colspan="3" valign="top"><code>b = a.sort {|a,b| (a.downcase <=> b.downcase).nonzero? || a <=> b }</code></td>
</tr>
<tr>
<td valign="top"><code>b</code></td>
<td valign="top"></td>
<td valign="top"><code>["A", "a", "AA", "Aa", "aA", "BB", "Bb", "bB", "bb", "z"]</code></td>
</tr>
</table>
<P></P>
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="remainder"><b>remainder</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.remainder( <i>aNumeric</i> )
-> <i>aNumeric</i>
</td></tr><td></td><td>
<P></P>
If <i>num</i> and <i>aNumeric</i> have different signs, returns
<em>mod</em>-<i>aNumeric</i>; otherwise, returns
<em>mod</em>. In both cases
<em>mod</em> is the value <i>num</i>.<code>modulo(</code><i>aNumeric</i><code>)</code>. The
differences between <code>remainder</code> and modulo (<code>%</code>) are
shown in Table 22.6 on page 355.
<P></P>
</td><tr><td valign="center" bgcolor="#ff9999"><font size="4"><a name="zero_qm"><b>zero?</b></a></font></td><td bgcolor="#ffaaaa">
<i>num</i>.zero? -> <code>true</code> or <code>false</code>
</td></tr><td></td><td>
<P></P>
Returns <code>true</code> if <i>num</i> has a zero value.
<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_nilclass.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_object.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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