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Converted to HTML in WebWorks Publisher 2000. manual wdt 1.5"> <META NAME="LASTUPDATED" CONTENT="09/28/00 13:15:44"> <TITLE> Core JavaScript Reference 1.5: </TITLE></HEAD><BODY TEXT="#000000" LINK="#666699" VLINK="#666699" ALINK="#333366" BGCOLOR="#FFFFFF"><MAINCONTENT><NAVIGATIONCONTENT> <TABLE WIDTH="100%" BORDER="0" CELLSPACING="4"> <TR> <TD VALIGN="TOP"> <b><a href="netscape.htm"><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Previous</a></FONT> </b><a href="contents.htm"><b><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Contents</a></FONT></b> <a href="ix.htm"><b><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Index</a></FONT></b> <a href="object.htm"><b><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Next</a></FONT></b> </TD> </TR> <TR> <TD VALIGN="TOP" ALIGN="RIGHT" BGCOLOR="#CCCCCC"> <FONT FACE="Arial, Helvetica, sans-serif" COLOR="#000000" SIZE="2"><B> Core JavaScript Reference 1.5</B></FONT> </TD> </TR> <TR> </TABLE> <BR></NAVIGATIONCONTENT><BOOKCONTENT> <blockquote><BR><BR> <BR><BR><P><A NAME="1193137"> </A><A NAME="Number"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="5"><B><zrefhead1>Number</zrefhead1></B></FONT><P><A NAME="1198237"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Lets you work with numeric values. The <FONT FACE="courier, couriernew, monospaced size">Number</FONT> object is an object wrapper for primitive numeric values.<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 COLSPAN=2 ROWSPAN=1><P><A NAME="1193141"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Core object</I></ztabletext></FONT></TD> </TR> <TR> <TD VALIGN=TOP><P><A NAME="1193145"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Implemented in</I></ztabletext></FONT> </TD> <TD VALIGN=TOP><P><A NAME="1193147"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.1, NES 2.0</ztabletext></FONT><P><A NAME="1193819"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext></ztabletext></FONT><P><A NAME="1193820"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.2: modified behavior of <FONT FACE="courier, couriernew, monospaced size">Number</FONT> constructor.</ztabletext></FONT><P><A NAME="1193151"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext></ztabletext></FONT><P><A NAME="1193821"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.3: added <A HREF="number.html#1201831" >toSource</A> method.</ztabletext></FONT><P><A NAME="1199080"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext></ztabletext></FONT><P><A NAME="1199117"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.5, NES 6.0: added <FONT FACE="courier, couriernew, monospaced size"><A HREF="number.html#1200968" >toExponential</A>, <A HREF="number.html#1200964" >toFixed</A>, and <A HREF="number.html#1201389" >toPrecision</A> </FONT>methods.</ztabletext></FONT> </TD> </TR> <TR> <TD VALIGN=TOP><P><A NAME="1194435"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>ECMA version</I></ztabletext></FONT> </TD> <TD VALIGN=TOP><P><A NAME="1194437"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>ECMA-262</ztabletext></FONT> </TD> </TR></TABLE><P></zparagraph></FONT><P><BR><A NAME="1193152"> </A><A NAME="Created by"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Created by</zrefheader></B></FONT><BR><A NAME="1193153"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>The <FONT FACE="courier, couriernew, monospaced size">Number</FONT> constructor:</zparagraph></FONT><P><A NAME="1193154"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>new Number(<I>value</I>)</zcodeline></FONT><P><BR><A NAME="1193155"> </A><A NAME="Parameters"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Parameters</zrefheader></B></FONT><BR><A NAME="1193161"> </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="1193158"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline>value</zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1193160"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><ztabletext>The numeric value of the object being created.</ztabletext></FONT> </TD> </TR></TABLE><P></zparagraph></FONT><P><BR><A NAME="1193162"> </A><A NAME="Description"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><B><zrefheader>Description</zrefheader></B></FONT><BR><A NAME="1193163"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>The primary uses for the <FONT FACE="courier, couriernew, monospaced size">Number</FONT> object are:</zparagraph></FONT><P><ul><A NAME="1193164"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><B> <li></B><zsmartlist1>To access its constant properties, which represent the largest and smallest representable numbers, positive and negative infinity, and the Not-a-Number value.</zsmartlist1></FONT><P><A NAME="1193165"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><B> <li></B><zsmartlist1>To create numeric objects that you can add properties to. Most likely, you will rarely need to create a <FONT FACE="courier, couriernew, monospaced size">Number</FONT> object.</zsmartlist1></FONT><P></ul><A NAME="1193166"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>The properties of <FONT FACE="courier, couriernew, monospaced size">Number</FONT> are properties of the class itself, not of individual <FONT FACE="courier, couriernew, monospaced size">Number</FONT> objects.</zparagraph></FONT><P><A NAME="1193167"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>JavaScript 1.2: <FONT FACE="courier, couriernew, monospaced size">Number(x)</FONT> now produces <FONT FACE="courier, couriernew, monospaced size">NaN</FONT> rather than an error if <FONT FACE="courier, couriernew, monospaced size">x</FONT> is a string that does not contain a well-formed numeric literal. For example, </zparagraph></FONT><P><A NAME="1193168"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline>x=Number("three");</zcodeline></FONT><P><A NAME="1193169"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline>document.write(x + "<BR>");</zcodeline></FONT><P><A NAME="1193170"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>prints <FONT FACE="courier, couriernew, monospaced size">NaN</FONT></zparagraph></FONT><P><A NAME="1197979"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>You can convert any object to a number using the top-level <A HREF="toplev.html#1064092" >Number</A> function.</zparagraph></FONT><P><BR><A NAME="1193171"> </A><A NAME="Property Summary"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><B><zrefheader>Property Summary</zrefheader></B></FONT><BR><A NAME="1193219"> </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 BGCOLOR="#CCCCCC" ALIGN=LEFT VALIGN=TOP> <TH VALIGN=TOP ALIGN=LEFT><A NAME="1193174"> </A><P ALIGN="LEFT"><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><B><ztablehead>Property</ztablehead></B></FONT></TH> <TH VALIGN=TOP ALIGN=LEFT><A NAME="1193176"> </A><P ALIGN="LEFT"><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><B><ztablehead>Description</ztablehead></B></FONT></TH> </DIV></TR> <TR> <TD VALIGN=TOP><A NAME="1196298"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline><A HREF="number.html#1196194" >constructor</A></zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1196300"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><ztabletext>Specifies the function that creates an object's prototype.</ztabletext></FONT> </TD> </TR> <TR> <TD VALIGN=TOP><A NAME="1193181"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline><A HREF="number.html#1193249" >MAX_VALUE</A></zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1193183"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><ztabletext>The largest representable number.</ztabletext></FONT> </TD> </TR> <TR> <TD VALIGN=TOP><A NAME="1193188"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline><A HREF="number.html#1193275" >MIN_VALUE</A></zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1193190"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><ztabletext>The smallest representable number.</ztabletext></FONT> </TD> </TR> <TR> <TD VALIGN=TOP><A NAME="1193195"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline><A HREF="number.html#1193302" >NaN</A></zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1193197"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><ztabletext>Special "not a number" value.</ztabletext></FONT> </TD> </TR> <TR> <TD VALIGN=TOP><A NAME="1193202"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline><A HREF="number.html#1193346" >NEGATIVE_INFINITY</A></zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1193204"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><ztabletext>Special value representing negative infinity; returned on overflow.</ztabletext></FONT> </TD> </TR> <TR> <TD VALIGN=TOP><A NAME="1193209"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline><A HREF="number.html#1193380" >POSITIVE_INFINITY</A></zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1193211"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><ztabletext>Special value representing infinity; returned on overflow.</ztabletext></FONT> </TD> </TR> <TR> <TD VALIGN=TOP><A NAME="1193216"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="-1"><zcodeline><A HREF="number.html#1193415" >prototype</A></zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1193218"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="-1"><ztabletext>Allows the addition of properties to a <FONT FACE="courier, couriernew, monospaced size">Number</FONT> object.</ztabletext></FONT> </TD> </TR></TABLE><P></zparagraph></FONT>⌨️ 快捷键说明
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