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📁 Programming and Problem Solving with C++
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">	<html>		<head>			<title>page_917</title>			<link rel="stylesheet" href="reset.css" type="text/css" media="all">			<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />		</head>		<body>		<table summary="top nav" border="0" width="100%">			<tr>				<td align="left" width="30%" style="background: #EEF3E2"><a style="color: blue; font-size: 120%; font-weight: bold; text-decoration: none; font-family: verdana;" href="page_916.html">&lt;&nbsp;previous page</a></td>				<td align="center" width="40%" style="background: #EEF3E2"><strong style="color: #2F4F4F; font-size: 120%;">page_917</strong></td>				<td align="right" width="30%" style="background: #EEF3E2"><a style="color: blue; font-size: 120%; font-weight: bold; text-decoration: none; font-family: verdana;" href="page_918.html">next page&nbsp;&gt;</a></td>			</tr>					<tr>				<td align="left" colspan="3" style="background: #ffffff; padding: 20px;">    <table border="0" width="100%" cellpadding="0"><tr><td align="center">  <table border="0" cellpadding="2" cellspacing="0" width="100%"><tr><td align="left"></td>  <td align="right"></td>  </tr></table></td></tr><tr><td align="left"><p></p><table border="0" cellspacing="0" cellpadding="0" width="100%"><tr><td align="right"><font face="Times New Roman, Times, Serif" size="2" color="#FF0000">Page 917</font></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td>  <td colspan="3" height="12"></td>  <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td>  <td><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">time2.Write();聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽//聽Outputs聽0:0:0聽EST<br />cout聽&lt;&lt;聽endl;<br /><br />time2.Set(16,聽49,聽23,聽CDT);<br />time2.Write();聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽//聽Outputs聽16:49:23聽CDT<br />cout聽&lt;&lt;聽endl;<br /><br />time1.Increment();<br />time1.Increment();聽聽聽聽聽聽聽聽聽聽聽聽聽聽//聽Outputs聽08:35:02聽PST<br />time1.Write();<br />cout聽&lt;&lt;聽endl;<br />聽聽.<br />聽聽.<br />聽聽.</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td>  <td colspan="3" height="12"></td>  <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td>  <td><font face="Times New Roman, Times, Serif" size="3"><i>Implementation of the </i></font><i><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">ExtTime</font><font face="Times New Roman, Times, Serif" size="3"> Class</font></i></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td>  <td colspan="3" height="12"></td>  <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td>  <td><font face="Times New Roman, Times, Serif" size="3">The implementation of the </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">ExtTime</font><font face="Times New Roman, Times, Serif" size="3"> class needs to deal only with the new features that are different from </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">Time</font><font face="Times New Roman, Times, Serif" size="3">. Specifically, we must write code to override the </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">Set</font><font face="Times New Roman, Times, Serif" size="3"> and </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">Write</font><font face="Times New Roman, Times, Serif" size="3"> functions and we must write the two constructors.</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td>  <td colspan="3" height="12"></td>  <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td>  <td><font face="Times New Roman, Times, Serif" size="3">With derived classes, constructors are subject to special rules. At run time, the base class constructor is implicitly called first, before the body of the derived class's constructor executes. Additionally, if the base class constructor requires parameters, these parameters must be passed by the derived class's constructor. To see how these rules pertain, let's examine the implementation file </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">exttime.cpp</font><font face="Times New Roman, Times, Serif" size="3"> (see Figure 16-6).</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td>  <td colspan="3" height="12"></td>  <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td>  <td><font face="Times New Roman, Times, Serif" size="3">Figure 16-6 </font><font face="Courier New, Courier, Mono New, Courier, Mono" size="3">ExtTime</font><font face="Times New Roman, Times, Serif" size="3"> Implementation File</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table><table border="0" cellspacing="0" cellpadding="0"><tr><td rowspan="5"></td>  <td colspan="3" height="12"></td>  <td rowspan="5"></td></tr><tr><td colspan="3"></td></tr><tr><td></td>  <td><font face="Courier New, Courier, Mono New, Courier, Mono" size="2">//******************************************************************<br />//聽IMPLEMENTATION聽FILE聽(exttime.cpp)<br />//聽This聽file聽implments聽the聽ExtTime聽member聽functions.<br />//聽The聽Time聽class聽is聽a聽public聽base聽class聽of聽ExtTime<br />//******************************************************************<br />#include聽exttime.h<br />#include聽&lt;聽iostream.h&gt;<br /><br />//聽Additional聽private聽members聽of聽class:<br />//聽聽聽聽聽ZoneType聽Zone;<br /><br />//******************************************************************<br /><br />ExtTime::ExtTime(聽/*聽in聽*/聽int聽聽聽聽聽聽initHrs,<br />聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽/*聽in聽*/聽int聽聽聽聽聽聽initMins,<br />聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽/*聽in聽*/聽int聽聽聽聽聽聽initSecs,<br />聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽/*聽in聽*/聽ZoneType聽initZone聽)<br /><br />聽聽聽聽:Time(initHrs,聽iniMins,聽iniSecs)<br /><br />//聽Constructor</font></td><td></td></tr><tr><td colspan="3"></td></tr><tr><td colspan="3" height="1"></td></tr></table></td></tr></table><p><font size="0"></font></p>聽  </td>			</tr>				<tr>				<td align="left" width="30%" style="background: #EEF3E2"><a style="color: blue; font-size: 120%; font-weight: bold; text-decoration: none; font-family: verdana;" href="page_916.html">&lt;&nbsp;previous page</a></td>				<td align="center" width="40%" style="background: #EEF3E2"><strong style="color: #2F4F4F; font-size: 120%;">page_917</strong></td>				<td align="right" width="30%" style="background: #EEF3E2"><a style="color: blue; font-size: 120%; font-weight: bold; text-decoration: none; font-family: verdana;" href="page_918.html">next page&nbsp;&gt;</a></td>			</tr>		</table>		</body>	</html>
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