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Converted to HTML in WebWorks Publisher 2000. manual wdt 1.5"> <META NAME="LASTUPDATED" CONTENT="09/28/00 13:15:35"> <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="javclass.html"><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Previous</a></FONT> </b><a href="contents.html"><b><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Contents</a></FONT></b> <a href="ix.html"><b><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Index</a></FONT></b> <a href="javpkg.html"><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="JavaObject"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="5"><B><zrefhead1>JavaObject</zrefhead1></B></FONT><P><A NAME="1193151"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>The type of a wrapped Java object accessed from within JavaScript code.<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="1193140"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Core object</I></ztabletext></FONT> </TD> <TD VALIGN=TOP><P><A NAME="1193142"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext></ztabletext></FONT> </TD> </TR> <TR> <TD VALIGN=TOP><P><A NAME="1193144"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext><I>Implemented in</I></ztabletext></FONT> </TD> <TD VALIGN=TOP><P><A NAME="1193146"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>JavaScript 1.1, NES 2.0</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>Any Java method which returns an object type. In addition, you can explicitly construct a <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT> using the object's Java constructor with the <FONT FACE="courier, couriernew, monospaced size">Packages</FONT> keyword:</zparagraph></FONT><P><A NAME="1196676"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>new Packages.<I>JavaClass</I>(<I>parameterList</I>)</zcodeline></FONT><P><A NAME="1196829"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>where <I>JavaClass</I> is the fully-specified name of the object's Java class.</zparagraph></FONT><P><BR><A NAME="1196800"> </A><A NAME="Parameters"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Parameters</zrefheader></B></FONT><BR><A NAME="1196814"> </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="1196803"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>parameterList</zcodeline></FONT><P> </TD> <TD VALIGN=TOP><P><A NAME="1196805"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><ztabletext>An optional list of parameters, specified by the constructor in the Java class.</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="2"><B><zrefheader>Description</zrefheader></B></FONT><BR><A NAME="1198206"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>The <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT> object is an instance of a Java class that is created in or passed to JavaScript. <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT> is a wrapper for the instance; all references to the class instance are made through the <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT>.</zparagraph></FONT><P><A NAME="1198350"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Any Java data brought into JavaScript is converted to JavaScript data types. When the <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT> is passed back to Java, it is unwrapped and can be used by Java code. See the <A HREF="http://developer.netscape.com/docs/manuals/js/core/jsguide/index.htm"><I>Core JavaScript Guide</I></A> for more information about data type conversions.</zparagraph></FONT><P><BR><A NAME="1197132"> </A><A NAME="Property Summary"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Property Summary</zrefheader></B></FONT><BR><A NAME="1197133"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Inherits public data members from the Java class of which it is an instance as properties. It also inherits public data members from any superclass as properties.</zparagraph></FONT><P><BR><A NAME="1197134"> </A><A NAME="Method Summary"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Method Summary</zrefheader></B></FONT><BR><A NAME="1196956"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Inherits public methods from the Java class of which it is an instance. The <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT> also inherits methods from <FONT FACE="courier, couriernew, monospaced size">java.lang.Object</FONT> and any other superclass.</zparagraph></FONT><P><BR><A NAME="1193209"> </A><A NAME="Examples"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>Examples</zrefheader></B></FONT><BR><A NAME="1194739"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><B>Example 1.</B> Instantiating a Java object in JavaScript.</zparagraph></FONT><P><A NAME="1197104"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>The following code creates the <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT> <FONT FACE="courier, couriernew, monospaced size">theString</FONT>, which is an instance of the class <FONT FACE="courier, couriernew, monospaced size">java.lang.String</FONT>:</zparagraph></FONT><P><A NAME="1198136"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>var theString = new Packages.java.lang.String("Hello, world")</zcodeline></FONT><P><A NAME="1197777"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Because the <FONT FACE="courier, couriernew, monospaced size">String</FONT> class is in the <FONT FACE="courier, couriernew, monospaced size">java</FONT> package, you can also use the <FONT FACE="courier, couriernew, monospaced size">java</FONT> synonym and omit the <FONT FACE="courier, couriernew, monospaced size">Packages</FONT> keyword when you instantiate the class:</zparagraph></FONT><P><A NAME="1198172"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>var theString = new java.lang.String("Hello, world")</zcodeline></FONT><P><A NAME="1198220"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><B>Example 2.</B> Accessing methods of a Java object.</zparagraph></FONT><P><A NAME="1198240"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Because the <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT> <FONT FACE="courier, couriernew, monospaced size">theString</FONT> is an instance of <FONT FACE="courier, couriernew, monospaced size">java.lang.String</FONT>, it inherits all the public methods of <FONT FACE="courier, couriernew, monospaced size">java.lang.String</FONT>. The following example uses the <FONT FACE="courier, couriernew, monospaced size">startsWith</FONT> method to check whether <FONT FACE="courier, couriernew, monospaced size">theString</FONT> begins with "Hello".</zparagraph></FONT><P><A NAME="1198234"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>var theString = new java.lang.String("Hello, world")<br>theString.startsWith("Hello") // returns true</zcodeline></FONT><P><A NAME="1198295"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><B>Example 3.</B> Accessing inherited methods.</zparagraph></FONT><P><A NAME="1198170"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph>Because <FONT FACE="courier, couriernew, monospaced size">getClass</FONT> is a method of <FONT FACE="courier, couriernew, monospaced size">Object</FONT>, and <FONT FACE="courier, couriernew, monospaced size">java.lang.String</FONT> extends <FONT FACE="courier, couriernew, monospaced size">Object</FONT>, the <FONT FACE="courier, couriernew, monospaced size">String</FONT> class inherits the <FONT FACE="courier, couriernew, monospaced size">getClass</FONT> method. Consequently, <FONT FACE="courier, couriernew, monospaced size">getClass</FONT> is also a method of the <FONT FACE="courier, couriernew, monospaced size">JavaObject</FONT> which instantiates <FONT FACE="courier, couriernew, monospaced size">String</FONT> in JavaScript.</zparagraph></FONT><P><A NAME="1198279"></A><FONT FACE="courier, couriernew, monospaced size" SIZE="2"><zcodeline>var theString = new java.lang.String("Hello, world")<br>theString.getClass() // returns java.lang.String</zcodeline></FONT><P><BR><A NAME="1198406"> </A><A NAME="See also"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><B><zrefheader>See also</zrefheader></B></FONT><BR><A NAME="1198277"> </A><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2"><zparagraph><A HREF="javarray.html#1193137" >JavaArray</A>, <A HREF="javclass.html#1193137" >JavaClass</A>, <A HREF="javpkg.html#1193137" >JavaPackage</A>, <A HREF="packages.html#1193137" >Packages</A></zparagraph></FONT><P> </BLOCKQUOTE></BOOKCONTENT><FOOTERCONTENT> <BLOCKQUOTE> <BR> <b><a href="javclass.html"><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Previous</a></FONT> </b><a href="contents.html"><b><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Contents</a></FONT></b> <a href="ix.html"><b><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Index</a></FONT></b> <a href="javpkg.html"><b><FONT FACE="Arial, Helvetica, sans-serif" SIZE="2" COLOR="#993300">Next</a></FONT></b> <HR NOSHADE SIZE="1"> <font face="Arial, Helvetica, sans-serif" SIZE="1">Copyright © 2000 <a href="http://www.netscape.com">Netscape Communications Corp.</a> All rights reserved.</FONT> </BLOCKQUOTE> <FONT FACE="Arial, Helvetica, sans-serif" SIZE="1"> <P ALIGN="RIGHT">Last Updated <B>September 28, 2000</B> </FONT> <BR></FOOTERCONTENT></MAINCONTENT></BODY></HTML>⌨️ 快捷键说明
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