<?xml version="1.0" encoding="utf-8"?>

<refentry xml:id="function.bcsqrt" xmlns="http://docbook.org/ns/docbook" xmlns:xi="http://www.w3.org/2001/XInclude">

<refnamediv>

<refname>bcsqrt</refname>

<refpurpose>Get the square root of an arbitrary precision number</refpurpose>

</refnamediv>

<refsect1 role="description">

&reftitle.description;

<methodsynopsis>

<type>string</type><methodname>bcsqrt</methodname>

<methodparam><type>string</type><parameter>num</parameter></methodparam>

<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 <parameter>num</parameter>.

</simpara>

</refsect1>

<refsect1 role="parameters">

&reftitle.parameters;

<para>

<variablelist>

<varlistentry>

<term><parameter>num</parameter></term>

<listitem>

<para>

The operand, as a well-formed BCMath numeric string.

</para>

</listitem>

</varlistentry>

<xi:include xpointer="function.bcadd..parameters.scale" />

</variablelist>

</para>

</refsect1>

<refsect1 role="returnvalues">

&reftitle.returnvalues;

<para>

Returns the square root as a well-formed BCMath numeric string.

</para>

</refsect1>

<refsect1 role="errors">

&reftitle.errors;

<para>

This function throws a <classname>ValueError</classname> in the following cases:

<simplelist>

<member><parameter>num</parameter> is not a well-formed BCMath numeric string</member>

<member><parameter>num</parameter> is less than <literal>0</literal></member>

<member><parameter>scale</parameter> is outside the valid range</member>

</simplelist>

</para>

</refsect1>

<refsect1 role="changelog">

&reftitle.changelog;

<informaltable>

<tgroup cols="2">

<thead>

<row>

<entry>&Version;</entry>

<entry>&Description;</entry>

</row>

</thead>

<tbody>

<row>

<entry>8.0.0</entry>

<entry>

If <parameter>num</parameter> is not a well-formed BCMath numeric string,

or less than <literal>0</literal>, a <classname>ValueError</classname> is thrown.

Previously, <constant>E_WARNING</constant> was raised instead.

</entry>

</row>

<row>

<entry>8.0.0</entry>

<entry>

<parameter>scale</parameter> now needs to be between <literal>0</literal>

and <literal>2147483647</literal>; previously, negative scales have been

silently treated as <literal>0</literal>.

</entry>

</row>

<row>

<entry>8.0.0</entry>

<entry>

<parameter>scale</parameter> is now nullable.

</entry>

</row>

</tbody>

</tgroup>

</informaltable>

</refsect1>

<refsect1 role="examples">

&reftitle.examples;

<example>

<title><function>bcsqrt</function> example</title>

<programlisting role="php">

</programlisting>

</example>

</refsect1>

<refsect1 role="seealso">

&reftitle.seealso;

<para>

<simplelist>

<member><function>bcpow</function></member>

<member><methodname>BcMath\Number::sqrt</methodname></member>

</simplelist>

</para>

</refsect1>

</refentry>