?? 10822_1.htm
字號:
<html>
<!-- #BeginTemplate "/Templates/empolder-doc.dwt" -->
<head>
<!-- #BeginEditable "title" -->
<title>JAVA程序員必讀：基礎篇 ---- |><| 太平洋電腦網 -> 網絡學院* 開發教室</title>
<!-- #EndEditable -->
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<style type="text/css">
<!--
-->
</style>
<link rel="stylesheet" href="/pcedu/style/text.css">
<script language="JavaScript">
<!--
function MM_swapImgRestore() { //v3.0
var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}
function MM_preloadImages() { //v3.0
var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}
function MM_swapImage() { //v3.0
var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
//-->
</script>
</head>
<body bgcolor="#FFFFFF" topmargin=0 leftmargin=0 marginheight="0" onLoad="MM_preloadImages('/images/lefton.gif','/images/topon.gif')">
<a name="top"></a>
<script language="JavaScript" src="/pcedu/script/top.js">
</script>
<table width=760 border=0 cellspacing=0 cellpadding=0 align=center>
<tr>
<td width=194 height="56"><a href=http://www.pconline.com.cn><img src=http://www.pconline.com.cn/images/pconlinelogo.gif width=162 height=35 vspace=10 border=0></a></td>
<td width=406 height="56">
<script language="JavaScript" src="/pcedu/script/empolder_ad.js">
</script>
</td>
<td width=158 align=right height="56">
<script language="JavaScript" src="/pcedu/script/empolder_ad1.js">
</script>
</td>
<td align=right width=2 height="56"> </td>
</tr>
</table>
<table border=0 cellpadding=0 cellspacing=0 width=760 align="center">
<tbody>
<tr valign=bottom>
<td rowspan=2 width=172><img height=32 src="/pcedu/images/pcedu_lo.gif"
width=172 border="0"></td>
<td height=30 rowspan=2>
<table cellpadding=0 cellspacing=0 width="588" bgcolor="#FFA000" background="/pcedu/images/e_menu5.gif" border="0">
<tbody>
<tr valign="bottom">
<td height="17">
<script language="JavaScript" src="/pcedu/script/title_empolder.js">
</script>
</td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr></tr>
<tr bgcolor="#303880">
<td colspan=2 height=1 valign=bottom><img height=1
src="/pcedu/images/blank.gif" width=1></td>
</tr>
<tr>
<td colspan=2 height=5 valign=bottom><img height=5
src="/pcedu/images/blank.gif" width=1></td>
</tr>
</tbody>
</table>
<table width="760" cellspacing="0" cellpadding="0" align="center" height="614">
<tr>
<td width="170" height="616" valign="top" rowspan="2">
<table border="0" width="170" height="100%"
cellspacing="1" bgcolor="#000000">
<tr bgcolor="#F8F8D2">
<td width="100%" valign="top" height="307">
<script language="JavaScript" src="/pcedu/script/left_empolder.js">
</script>
</td>
</tr>
</table>
</td>
<td width="8" height="308"><img src="/pcedu/images/blank.gif" width="1" height="1"></td>
<td valign="top" height="444" width="582">
<table width="582" border="0" cellspacing="0" cellpadding="0" height="1" background="/images/line5.gif">
<tr>
<td height="1"></td>
</tr>
</table>
<!-- #BeginEditable "content" -->
<table width="582" border="0" cellspacing="8" cellpadding="0" background="/images/bg6.gif">
<tr>
<td valign="top">
<table width="100%" border="0" cellspacing="8" cellpadding="0" background="/images/point.gif">
<tr>
<td height="4" colspan="3"></td>
</tr>
<tr>
<td height="22" colspan="3">
<div align="center" class="title">JAVA程序員必讀：基礎篇（4）對象和簡單數據對象</div>
</td>
</tr>
<tr valign="bottom">
<td width="90" height="18">
<div align="right" class="gray"> </div>
<div class="gray"></div>
</td>
<td height="18">
<div align="center"><font color="#666666">編譯：ZSC/太平洋網絡學院</font></div>
</td>
<td width="90">
<div align="right" class="gray"><a href="mailto:tntst@pconline.com.cn">［責編:爆破手］</a></div>
</td>
</tr>
<tr valign="bottom">
<td colspan="3" height="0"></td>
</tr>
</table>
<p class="article"><b>對象和簡單數據對象</b></p>
<p></p>
<p class="article"><span class="article"><b>4.1.1.3 初始化對象</b></span></p>
<p></p>
<p class="article">下面是Rectangle類的代碼，它包含了四個構造函數： </p>
<p class="article"><span class="blue">public class Rectangle {</span></p>
<p class="article"><span class="blue"> public int width = 0;</span></p>
<p class="article"><span class="blue"> public int height = 0;</span></p>
<p class="article"><span class="blue"> public Point origin;</span></p>
<p></p>
<p class="article"><span class="blue"> //四個構造函數</span></p>
<p class="article"><span class="blue"> public Rectangle() {</span></p>
<p class="article"><span class="blue"> origin = new Point(0, 0);</span></p>
<p class="article"><span class="blue"> }</span></p>
<p class="article"><span class="blue"> public Rectangle(Point p) {</span></p>
<p class="article"><span class="blue"> origin = p;</span></p>
<p class="article"><span class="blue"> }</span></p>
<p class="article"><span class="blue"> public Rectangle(int w, int
h) {</span></p>
<p class="article"><span class="blue"> this(new Point(0, 0), w, h);</span></p>
<p class="article"><span class="blue"> }</span></p>
<p class="article"><span class="blue"> public Rectangle(Point p, int
w, int h) {</span></p>
<p class="article"><span class="blue"> origin = p;</span></p>
<p class="article"><span class="blue"> width = w;</span></p>
<p class="article"><span class="blue"> height = h;</span></p>
<p class="article"><span class="blue"> }</span></p>
<p class="article"><span class="blue"> //用于移動rectangle的方法</span></p>
<p class="article"><span class="blue"> public void move(int x, int
y) {</span></p>
<p class="article"><span class="blue"> origin.x = x;</span></p>
<p class="article"><span class="blue"> origin.y = y;</span></p>
<p class="article"><span class="blue"> }</span></p>
<p class="article"><span class="blue"> //用于計算矩形面積的方法</span></p>
<p class="article"><span class="blue"> public int area() {</span></p>
<p class="article"><span class="blue"> return width * height;</span></p>
<p class="article"><span class="blue"> }</span></p>
<p class="article"><span class="blue">}</span></p>
<p class="article"> 每一個構造函數可以讓你為矩形的各個方法提供初始數值，你可以設置矩形的原點、寬度和高度。如果一個類中有多個構造函數，它們的名字都是相同的只是它們有不同類型的參數或者不同數目的參數。JAVA平臺可以根據參數的不同數目和類型類來區分構造函數。當JAVA平臺遇到的代碼的時候，它就調用在Rectangle類中的構造函數，這個函數需要一個Point參數以及兩個整型參數：
</p>
<p class="article"> Rectangle rect_one = new Rectangle(origin_one,
100, 200);</p>
<p class="article"> 這個調用初始化了矩形的原點（orgin_one）。代碼也設置了矩形的寬度（100）和高度（200）。</p>
<p align="center" class="article"><a href="10822.htm">[上一頁]</a> <a href="10822_2.htm">[下一頁]</a></p>
</td>
</tr>
<tr bgcolor="#FF6600">
<td height="1"></td>
</tr>
<tr>
<td>
<table width="100%" border="0" cellspacing="0" cellpadding="0" background="/images/point.gif">
<tr>
<td colspan="2">
<p align="center" class="basicfont"><br>
如果您有什么疑問或看法請到 <a href="http://home.pconline.com.cn/cgi-bin/newbbs/bbs_login.cgi?loginname=guest&loginpasswd=guest" target="_blank" class="blue">精彩論壇</a>
發表意見<br>
</p>
<p align="center" class="basicfont"><font color=#ff0000><b class="article">未經同意
不得轉載</b></font></p>
<p align="center" class="basicfont"> <span class="basicfont"><a href="javascript:history.back(-1)" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('image3','','/images/lefton.gif',1)"><img src="/images/LEFTOFF.GIF" border="0" name="image3" alt="返回" width="19" height="22"></a>
<a href="#top" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('image2','','/images/topon.gif',1)"><img src="/images/TOPOFF.GIF" name="image2" border="0" alt="頁首" width="22" height="22"></a></span></p>
</td>
</tr>
</table>
</td>
</tr>
</table>
<!-- #EndEditable -->
<table width="582" border="0" cellspacing="0" cellpadding="0" height="1" background="/images/line5.gif">
<tr>
<td height="1"></td>
</tr>
</table>
<script
src=/script/hotfiles.js>
</script>
</td>
</tr>
</table>
<hr noshade size="2" width="760">
<p align="center">
<script language="JavaScript" src="/pcedu/script/title_edu.js">
</script>
<br>
<br>
版權所有©2000 太平洋電腦網<br>
<font face="Arial, Helvetica, sans-serif"> <a href=mailto:webmaster@pconline.com.cn>webmaster@pconline.com.cn
</a>
<script language="">
document.write("<a href=http://count.pconline.com.cn/admin/index.php target=_blank><img src=http://count.pconline.com.cn/count.php?user=pcedu&refer="+escape(document.referrer)+" border=0 width=0 height=0 alt='' ></a>");
</script>
</font></p>
</body>
<!-- #EndTemplate -->
</html>
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -