</FONT><P><BR><BR><A NAME="1064064"> </A><A NAME="NaN"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="4"><zhead1>NaN</zhead1><HR SIZE="2" NOSHADE></FONT><BR><A NAME="1064074"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>A value representing Not-A-Number.<BR><P><TABLE WIDTH="90%" BORDER="1" CELLPADDING="5" CELLSPACING="0">  <CAPTION></CAPTION><P><FONT FACE=""><B></B></FONT><BR><BR>  <TR>    <TD VALIGN=TOP><P><A NAME="1064067"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Core property</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1064069"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext></ztabletext></FONT>&nbsp;</TD>  </TR>  <TR>    <TD VALIGN=TOP><P><A NAME="1064071"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Implemented in</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1064073"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.3 (In previous versions, <FONT FACE="courier, couriernew, monospaced size">NaN</FONT> was defined only as a property of the <FONT FACE="courier, couriernew, monospaced size">Number</FONT> object)</ztabletext></FONT>&nbsp;</TD>  </TR>  <TR>    <TD VALIGN=TOP><P><A NAME="1074359"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>ECMA version</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1074361"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>ECMA-262</ztabletext></FONT>&nbsp;</TD>  </TR></TABLE><P></zparagraph></FONT><P><BR><A NAME="1064075"> </A><A NAME="Syntax"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Syntax</zrefheader></B></FONT><BR><A NAME="1064076"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>NaN</zcodeline></FONT><P><BR><A NAME="1064077"> </A><A NAME="Description"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Description</zrefheader></B></FONT><BR><A NAME="1064078"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><FONT FACE="courier, couriernew, monospaced size">NaN</FONT> is a top-level property and is not associated with any object.</zparagraph></FONT><P><A NAME="1099595"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>The initial value of <FONT FACE="courier, couriernew, monospaced size">NaN</FONT> is NaN.</zparagraph></FONT><P><A NAME="1064079"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><FONT FACE="courier, couriernew, monospaced size">NaN</FONT> is always unequal to any other number, including NaN itself; you cannot check for the not-a-number value by comparing to <FONT FACE="courier, couriernew, monospaced size">Number.NaN</FONT>. Use the <FONT FACE="courier, couriernew, monospaced size">isNaN</FONT> function instead.</zparagraph></FONT><P><A NAME="1064080"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Several JavaScript methods (such as the <FONT FACE="courier, couriernew, monospaced size">Number</FONT> constructor, <FONT FACE="courier, couriernew, monospaced size">parseFloat</FONT>, and <FONT FACE="courier, couriernew, monospaced size">parseInt</FONT>) return <FONT FACE="courier, couriernew, monospaced size">NaN</FONT> if the value specified in the parameter is not a number.</zparagraph></FONT><P><A NAME="1064081"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>You might use the <FONT FACE="courier, couriernew, monospaced size">NaN</FONT> property to indicate an error condition for a function that should return a valid number.</zparagraph></FONT><P><BR><A NAME="1064082"> </A><A NAME="See also"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>See also</zrefheader></B></FONT><BR><A NAME="1064089"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><A HREF="toplev.htm#1064024"  >isNaN</A>, <A HREF="number.htm#1193302"  >Number.NaN</A></zparagraph></FONT><P><BR><BR><A NAME="1064092"> </A><A NAME="Number"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="4"><zhead1>Number</zhead1><HR SIZE="2" NOSHADE></FONT><BR><A NAME="1064102"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Converts the specified object to a number. <BR><P><TABLE WIDTH="90%" BORDER="1" CELLPADDING="5" CELLSPACING="0">  <CAPTION></CAPTION><P><FONT FACE=""><B></B></FONT><BR><BR>  <TR>    <TD VALIGN=TOP><P><A NAME="1064095"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Core function</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1064097"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext></ztabletext></FONT>&nbsp;</TD>  </TR>  <TR>    <TD VALIGN=TOP><P><A NAME="1064099"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Implemented in</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1064101"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.2, NES 3.0</ztabletext></FONT>&nbsp;</TD>  </TR>  <TR>    <TD VALIGN=TOP><P><A NAME="1074373"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>ECMA version</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1074375"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>ECMA-262</ztabletext></FONT>&nbsp;</TD>  </TR></TABLE><P></zparagraph></FONT><P><BR><A NAME="1064103"> </A><A NAME="Syntax"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Syntax</zrefheader></B></FONT><BR><A NAME="1064104"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>Number(<I>obj</I>)</zcodeline></FONT><P><BR><A NAME="1064105"> </A><A NAME="Parameter"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Parameter</zrefheader></B></FONT><BR><A NAME="1064111"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><BR><P><TABLE WIDTH="90%" BORDER="1" CELLPADDING="5" CELLSPACING="0">  <CAPTION></CAPTION><P><FONT FACE=""><B></B></FONT><BR><BR>  <TR>    <TD VALIGN=TOP><A NAME="1064108"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>obj</zcodeline></FONT><P>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1064110"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>An object.</ztabletext></FONT>&nbsp;</TD>  </TR></TABLE><P></zparagraph></FONT><P><BR><A NAME="1064112"> </A><A NAME="Description"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Description</zrefheader></B></FONT><BR><A NAME="1097674"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><FONT FACE="courier, couriernew, monospaced size">Number</FONT> is a top-level function and is not associated with any object.</zparagraph></FONT><P><A NAME="1064116"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>When the object is a <A HREF="date.htm#1193137"  >Date</A> object, <FONT FACE="courier, couriernew, monospaced size">Number</FONT> returns a value in milliseconds measured from 01 January, 1970 UTC (GMT), positive after this date, negative before. </zparagraph></FONT><P><A NAME="1064117"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>If <FONT FACE="courier, couriernew, monospaced size">obj</FONT> is <font face="fontsansserif" SIZE="5" COLOR="red">a string that does not contain a well-formed numeric literal, </font><FONT FACE="courier, couriernew, monospaced size">Number</FONT> returns NaN.</zparagraph></FONT><P><BR><A NAME="1064118"> </A><A NAME="Example"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Example</zrefheader></B></FONT><BR><A NAME="1064122"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>The following example converts the <A HREF="date.html#1193137"  >Date</A> object to a numerical value: </zparagraph></FONT><P><A NAME="1073478"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>d = new Date ("December 17, 1995 03:24:00")<br>alert (Number(d))</zcodeline></FONT><P><A NAME="1064124"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>This displays a dialog box containing "819199440000." </zparagraph></FONT><P><BR><A NAME="1064125"> </A><A NAME="See also"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>See also</zrefheader></B></FONT><BR><A NAME="1064129"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><A HREF="number.html#1193137"  >Number</A></zparagraph></FONT><P><BR><BR><A NAME="1064132"> </A><A NAME="parseFloat"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="4"><zhead1>parseFloat</zhead1><HR SIZE="2" NOSHADE></FONT><BR><A NAME="1064143"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Parses a string argument and returns a floating point number.<BR><P><TABLE WIDTH="90%" BORDER="1" CELLPADDING="5" CELLSPACING="0">  <CAPTION></CAPTION><P><FONT FACE=""><B></B></FONT><BR><BR>  <TR>    <TD VALIGN=TOP><P><A NAME="1064135"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Core function</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1064137"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext></ztabletext></FONT>&nbsp;</TD>  </TR>  <TR>    <TD VALIGN=TOP><P><A NAME="1064139"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Implemented in</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1064141"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.0: If the first character of the string specified in parseFloat(<FONT FACE="courier, couriernew, monospaced size">string</FONT>) cannot be converted to a number, returns <FONT FACE="courier, couriernew, monospaced size">NaN</FONT> on Solaris and Irix and 0 on all other platforms.</ztabletext></FONT><P><A NAME="1070201"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext></ztabletext></FONT><P><A NAME="1064142"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.1, NES 2.0: Returns <FONT FACE="courier, couriernew, monospaced size">NaN</FONT> on all platforms if the first character of the string specified in parseFloat(<FONT FACE="courier, couriernew, monospaced size">string</FONT>) cannot be converted to a number.</ztabletext></FONT>&nbsp;</TD>  </TR>  <TR>    <TD VALIGN=TOP><P><A NAME="1074386"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>ECMA version</I></ztabletext></FONT>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1074388"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>ECMA-262</ztabletext></FONT>&nbsp;</TD>  </TR></TABLE><P></zparagraph></FONT><P><BR><A NAME="1064144"> </A><A NAME="Syntax"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Syntax</zrefheader></B></FONT><BR><A NAME="1064145"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>parseFloat(<I>string</I>)</zcodeline></FONT><P><BR><A NAME="1064146"> </A><A NAME="Parameters"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Parameters</zrefheader></B></FONT><BR><A NAME="1064152"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><BR><P><TABLE WIDTH="90%" BORDER="1" CELLPADDING="5" CELLSPACING="0">  <CAPTION></CAPTION><P><FONT FACE=""><B></B></FONT><BR><BR>  <TR>    <TD VALIGN=TOP><A NAME="1064149"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>string</zcodeline></FONT><P>&nbsp;</TD>    <TD VALIGN=TOP><P><A NAME="1064151"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>A string that represents the value you want to parse.</ztabletext></FONT>&nbsp;</TD>  </TR></TABLE><P></zparagraph></FONT><P><BR><A NAME="1064153"> </A><A NAME="Description"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Description</zrefheader></B></FONT><BR><A NAME="1097866"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><FONT FACE="courier, couriernew, monospaced size">parseFloat</FONT> is a top-level function and is not associated with any object.</zparagraph></FONT><P><A NAME="1064155"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><FONT FACE="courier, couriernew, monospaced size">parseFloat</FONT> parses its argument, a string, and returns a floating point number. If it encounters a chara