<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >pi</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="Manual do PHP" HREF="index.html"><LINK REL="UP" TITLE="Matemática e Trigonometria" HREF="ref.math.html"><LINK REL="PREVIOUS" TITLE="octdec" HREF="function.octdec.html"><LINK REL="NEXT" TITLE="pow" HREF="function.pow.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"></HEAD ><BODY CLASS="refentry" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Manual do PHP</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="function.octdec.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="function.pow.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.pi" ></A >pi</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN105160" ></A ><P > (PHP 3, PHP 4, PHP 5)</P >pi -- Obtêm o valor de pi</DIV ><DIV CLASS="refsect1" ><A NAME="AEN105163" ></A ><H2 >Descrição</H2 >float <B CLASS="methodname" >pi</B > ( void )<BR ></BR ><P > Retorna o valor aproximado de Pi. O valor retornado <A HREF="language.types.float.html" ><B CLASS="type" >float</B ></A > tem a precisão baseada na diretiva <A HREF="ini.core.html#ini.precision" >precision</A > do <TT CLASS="filename" >php.ini</TT >, que tem por padrão <TT CLASS="literal" >14</TT >. Também é possivel usar a constante <TT CLASS="constant" ><B >M_PI</B ></TT > que terá resultados idênticos a <B CLASS="function" >pi()</B >. </P ><P > <DIV CLASS="informalexample" ><P ></P ><A NAME="AEN105177" ></A ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><PRE CLASS="programlisting" ><?php echo pi(); // 3.1415926535898 echo M_PI; // 3.1415926535898 ?></PRE ></TD ></TR ></TABLE ><P ></P ></DIV > </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="function.octdec.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Principal</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.pow.html" ACCESSKEY="N" >Próxima</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >octdec</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.math.html" ACCESSKEY="U" >Acima</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >pow</TD ></TR ></TABLE ></DIV ></BODY ></HTML >