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<?xml version="1.0" encoding="utf-8"?>
<refentry xml:id="bcmath-number.sqrt" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xi="http://www.w3.org/2001/XInclude">
<refnamediv>
<refname>BcMath\Number::sqrt</refname>
<refpurpose>Gets the square root of an arbitrary precision number</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis role="BcMath\\Number">
<modifier>public</modifier> <type>BcMath\Number</type><methodname>BcMath\Number::sqrt</methodname>
<methodparam choice="opt"><type class="union"><type>int</type><type>null</type></type><parameter>scale</parameter><initializer>&null;</initializer></methodparam>
</methodsynopsis>
<simpara>
Return the square root of <varname>$this</varname>.
</simpara>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<variablelist>
<xi:include xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('bcmath-number.add')/db:refsect1[@role='parameters']/descendant::db:varlistentry[2])" />
</variablelist>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<simpara>
Returns the square root as a new <classname>BcMath\Number</classname> object.
</simpara>
<simpara>
When the <property>BcMath\Number::scale</property> of the result object is automatically set,
the <property>BcMath\Number::scale</property> of <varname>$this</varname> is used. However, in cases such
as indivisible division, the <property>BcMath\Number::scale</property> of the result is expanded.
Expansion is done only as needed, up to a maximum of <literal>+10</literal>.
This behavior is the same as <methodname>BcMath\Number::div</methodname>, so please see that for details.
</simpara>
<simpara>
That is, if the <property>BcMath\Number::scale</property> of <varname>$this</varname> is <literal>5</literal>,
the <property>BcMath\Number::scale</property> of the result is between <literal>5</literal> and
<literal>15</literal>.
</simpara>
</refsect1>
<refsect1 role="errors">
&reftitle.errors;
<para>
This method throws a <exceptionname>ValueError</exceptionname> in the following cases:
<simplelist>
<member><varname>$this</varname> is a negative value</member>
<member><parameter>scale</parameter> is outside the valid range</member>
<member><property>BcMath\Number::scale</property> of the result object is outside the valid range</member>
</simplelist>
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<example>
<title><methodname>BcMath\Number::sqrt</methodname> example</title>
<programlisting role="php">
<![CDATA[
<?php
var_dump(
new BcMath\Number('2')->sqrt(),
new BcMath\Number('2')->sqrt(3),
new BcMath\Number('4')->sqrt(),
new BcMath\Number('4')->sqrt(3),
);
?>
]]>
</programlisting>
&example.outputs;
<screen>
<![CDATA[
object(BcMath\Number)#2 (2) {
["value"]=>
string(12) "1.4142135623"
["scale"]=>
int(10)
}
object(BcMath\Number)#3 (2) {
["value"]=>
string(5) "1.414"
["scale"]=>
int(3)
}
object(BcMath\Number)#4 (2) {
["value"]=>
string(1) "2"
["scale"]=>
int(0)
}
object(BcMath\Number)#5 (2) {
["value"]=>
string(5) "2.000"
["scale"]=>
int(3)
}
]]>
</screen>
</example>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<simplelist>
<member><function>bcsqrt</function></member>
<member><methodname>BcMath\Number::div</methodname></member>
<member><methodname>BcMath\Number::pow</methodname></member>
</simplelist>
</refsect1>
</refentry>
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