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SHAPE ="RECT" HREF ="/reference/author.html" COORDS ="361,0,440,29"><AREA SHAPE ="RECT" HREF ="/reference/basic.html" COORDS ="254,0,360,29"><AREA SHAPE ="RECT" HREF ="/reference/help.html" COORDS ="183,0,251,29"><AREA SHAPE ="RECT" HREF ="/reference/cool.html" COORDS ="100,0,181,29"><AREA SHAPE ="RECT" HREF ="/reference/mybook.html" COORDS ="0,0,100,29"></MAP><MAP NAME ="header_r1.gif.map"><AREA SHAPE ="RECT" HREF ="/reference/personalize.html" COORDS ="339,0,439,29"></MAP><p><font face="Arial,Helvetica" size="-1" color="#006666"><A HREF="/reference/r_library.html"><B>All Categories</A> :</B><b><A HREF="/reference/r_java.html">Java</A></b></font><p><META><H1><FONT SIZE=6 COLOR=#Ff0000>Appendix A</FONT></H1><H1><FONT SIZE=6 COLOR=#Ff0000>Answers to Review Questions</FONT></H1><HR><P><CENTER><B><FONT SIZE=5><A NAME="CONTENTS">CONTENTS</A></FONT></B></CENTER><UL><LI><A HREF="#Chapter1">Chapter 1</A><LI><A HREF="#Chapter2">Chapter 2</A><LI><A HREF="#Chapter3">Chapter 3</A><LI><A HREF="#Chapter4">Chapter 4</A><LI><A HREF="#Chapter5">Chapter 5</A><LI><A HREF="#Chapter6">Chapter 6</A><LI><A HREF="#Chapter7">Chapter 7</A><LI><A HREF="#Chapter8">Chapter 8</A><LI><A HREF="#Chapter9">Chapter 9</A><LI><A HREF="#Chapter10">Chapter 10</A><LI><A HREF="#Chapter11">Chapter 11</A><LI><A HREF="#Chapter12">Chapter 12</A><LI><A HREF="#Chapter13">Chapter 13</A><LI><A HREF="#Chapter14">Chapter 14</A><LI><A HREF="#Chapter15">Chapter 15</A><LI><A HREF="#Chapter16">Chapter 16</A><LI><A HREF="#Chapter17">Chapter 17</A><LI><A HREF="#Chapter18">Chapter 18</A><LI><A HREF="#Chapter19">Chapter 19</A><LI><A HREF="#Chapter20">Chapter 20</A><LI><A HREF="#Chapter21">Chapter 21</A><LI><A HREF="#Chapter22">Chapter 22</A><LI><A HREF="#Chapter23">Chapter 23</A><LI><A HREF="#Chapter24">Chapter 24</A><LI><A HREF="#Chapter25">Chapter 25</A><LI><A HREF="#Chapter26">Chapter 26</A><LI><A HREF="#Chapter27">Chapter 27</A><LI><A HREF="#Chapter28">Chapter 28</A><LI><A HREF="#Chapter29">Chapter 29</A><LI><A HREF="#Chapter30">Chapter 30</A><LI><A HREF="#Chapter31">Chapter 31</A><LI><A HREF="#Chapter32">Chapter 32</A><LI><A HREF="#Chapter33">Chapter 33</A><LI><A HREF="#Chapter34">Chapter 34</A><LI><A HREF="#Chapter35">Chapter 35</A><LI><A HREF="#Chapter36">Chapter 36</A></UL><HR><H2><A NAME="Chapter1"><FONT SIZE=5 COLOR=#Ff0000>Chapter 1</FONT></A></H2><OL><LI>Probably the three most important reasons that Java is sosuitable for Internet applications are the language's robustness,simplicity, and, most importantly, its security features.<LI>A Java applet is a small program that is embedded in an HTMLdocument and is run when the document is loaded. A Java standaloneapplication doesn't need to be embedded in an HTML document andcan be run just like any other application.<LI>Java applets are compiled into byte-code files that can beexecuted by any computer that has a Java interpreter.<LI>Applets are handled in an HTML document similarly to elementslike images. The applet is referenced in the HTML document, whichcauses the HTML document to load and run the applet.<LI>Java is platform-independent so that it can run on any system.Java is also multithreaded, which means it can handle multipletasks concurrently and run fast.</OL><H2><A NAME="Chapter2"><FONT SIZE=5 COLOR=#Ff0000>Chapter 2</FONT></A></H2><OL><LI>Use the Appletviewer tool included with the JDK.<LI>The required attributes are <TT>code</TT>, <TT>width</TT>,and <TT>height</TT>.<LI>The <TT>codebase</TT> attribute specifies the location ofan applet's code (the .CLASS file). The given folder is relativeto the folder of the HTML document that contains the referenceto the applet.<LI>Other optional attributes include <TT>alt</TT>, <TT>align</TT>,<TT>name</TT>, <TT>hspace</TT>, and <TT>vspace</TT>.<LI>Applet parameters enable a user to configure an applet tofit his specific needs.<LI>You can provide alternate content for non-Java browsers. Youdo this by placing standard HTML script commands for the alternatecontent right before the ending <TT></applet></TT> tag.</OL><H2><A NAME="Chapter3"><FONT SIZE=5 COLOR=#Ff0000>Chapter 3</FONT></A></H2><OL><LI>A local applet is located on your computer system.<LI>A remote applet is located on another computer system andmust be downloaded onto your computer before it can be run.<LI>The client is the computer that requests information (in thiscase, an applet) from another computer. The computer that suppliesthe information is the server.<LI>Once applets can flow both from and to a remote computer,the client/server relationship will become less important. Thisis because computers will keep switching from being a client anda server.<LI>The Java interpreter validates every applet before the appletis run. This prevents applets that have been modified (maybe byhaving a virus attached) from affecting the destination system.The validation process also ensures that an applet cannot crashthe system.</OL><H2><A NAME="Chapter4"><FONT SIZE=5 COLOR=#Ff0000>Chapter 4</FONT></A></H2><OL><LI>When you use top-down programming, you divide a program upsuch that the detail goes from general to specific as you workyour way down the program.<LI>Top-down programming enables you to separate the general tasksthat must be completed by a program from the details that implementthose tasks, making a program easier to understand and organize.<LI>OOP offers another organizational level to the programmer.Not only can the programmer divide tasks up into logical chunksin top-down, structured fashion, but he can also separate logicalelements of the program into objects.<LI>The two main elements of a class are data fields and the methodsthat operate on the data fields.<LI>A class is like a template or blueprint for an object. Anobject is an instance of the class.<LI>The three main OOP concepts are encapsulation, inheritance,and polymorphism.<LI>Encapsulation is the act of enclosing both the data and thefunctions that act on the data within the object. Inheritanceis the ability of a new object (a derived object) to inherit dataand functions from a base object. Polymorphism is the abilityof a derived object to implement a function of the base classin a different way.</OL><H2><A NAME="Chapter5"><FONT SIZE=5 COLOR=#Ff0000>Chapter 5</FONT></A></H2><OL><LI>A constant is a value that can't be changed during a program'sexecution. Constants have symbolic names like <TT>PI</TT> or <TT>NUMBEROFITEMS</TT>.<LI>A variable is a value that can be changed as much as neededduring a program's execution. Like constants, variables have symbolicnames. Examples of variable names are <TT>count</TT> and <TT>area_of_circle</TT>.<LI>Constants and variables replace hard-to-understand valueswith English-like names. Moreover, variables enable you to namea value that must change many times during program execution.<LI>Java's eight data types are <TT>byte</TT>, <TT>short</TT>,<TT>int</TT>, <TT>long</TT>, <TT>float</TT>, <TT>double</TT>,<TT>char</TT>, and <TT>boolean</TT>.<LI>Variable scope determines where in a program a variable canbe accessed. A variable goes into scope at the beginning of theprogram block in which the variable is declared and goes out ofscope at the end of the block.</OL><H2><A NAME="Chapter6"><FONT SIZE=5 COLOR=#Ff0000>Chapter 6</FONT></A></H2><OL><LI>Graphical text is text that must be drawn on the screen justlike other shapes such as circles and squares, rather than printedusing a built-in character set as is done under MS-DOS.<LI>In a proportional font, each letter takes up only the amountof space it needs, whereas every letter in a non-proportionalfont takes up exactly the same amount of space.<LI>Arguments are values that are sent to a method when the methodis called.<LI>The three arguments for the <TT>drawString()</TT> method are⌨️ 快捷键说明
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