1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<book xml:id="book.bc" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
<?phpdoc extension-membership="bundled" ?>
<title>BCMath Arbitrary Precision Mathematics</title>
<titleabbrev>BC Math</titleabbrev>
<!-- {{{ preface -->
<preface xml:id="intro.bc">
&reftitle.intro;
<para>
For arbitrary precision mathematics PHP offers BCMath which
supports numbers of any size and precision up to <literal>2147483647</literal> (or <literal>0x7FFFFFFF</literal>) decimal digits,
if there is sufficient memory, represented as strings.
</para>
<para>
Valid (aka. well-formed) BCMath numbers are strings which match the regular expression
<literal>/^[+-]?[0-9]*(\.[0-9]*)?$/</literal>.
</para>
<caution>
<para>
Passing values of type <type>float</type> to a BCMath function which expects
a <type>string</type> as operand may not have the desired effect due to the
way PHP converts <type>float</type> values to <type>string</type>, namely
that the <type>string</type> may be in exponential notation (which is not
supported by BCMath), and that, prior to PHP 8.0.0, the decimal separator is locale dependent
(while BCMath always expects a decimal point).
</para>
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
$num1 = 0; // (string) 0 => '0'
$num2 = -0.000005; // (string) -0.000005 => '-5.05E-6'
echo bcadd($num1, $num2, 6); // => '0.000000'
setlocale(LC_NUMERIC, 'de_DE'); // uses a decimal comma
$num2 = 1.2; // (string) 1.2 => '1,2'
echo bcsub($num1, $num2, 1); // => '0.0'
?>
]]>
</programlisting>
</informalexample>
</caution>
</preface>
<!-- }}} -->
&reference.bc.setup;
&reference.bc.reference;
&reference.bc.bcmath.number;
</book>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->
|
