📄 [c++对象模型][3]指针与数组 - itech's blog - 博客园.htm

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style="COLOR: #000000">-&gt;</SPAN><SPAN 
style="COLOR: #000000">name&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800000">"</SPAN><SPAN style="COLOR: #800000">jason</SPAN><SPAN 
style="COLOR: #800000">"</SPAN><SPAN style="COLOR: #000000">;&nbsp;</SPAN><SPAN 
style="COLOR: #008000">//</SPAN><SPAN 
style="COLOR: #008000">&nbsp;此时的name指向了常量区，所以name指针不需要程序员释放。</SPAN><SPAN 
style="COLOR: #008000"><BR></SPAN><SPAN 
style="COLOR: #000000">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;free(&nbsp;willy&nbsp;);<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;willy&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN 
style="COLOR: #000000">&nbsp;NULL;<BR>}</SPAN></SPAN></DIV>
<P>&nbsp;</P>
<P><SPAN style="COLOR: #000000">malloc/free 和new/delete的区别：</SPAN></P>
<P><SPAN style="COLOR: #ff0000">1）new/delete是保留字,不需要头文件支持. 
malloc/free需要头文件库函数支持. 使用malloc/free需要包含 #include&lt;cstdlib&gt; 
或&lt;stdlib&gt;<SPAN class=co2>.</SPAN></SPAN></P>
<P><SPAN style="COLOR: #ff0000"><SPAN class=co2>2) </SPAN>new 
建立的是一个对象,new会根据对象计算大小，直接返回对象的指针，当使用完毕后调用delete来释放，但malloc分配的是一块内存，需要用户制定所要分配内存的大小，而且返回的均为void的指针，使用时需要相应的强制类型转化，使用结束后调用free来释放内存.</SPAN></P>
<P><SPAN 
style="COLOR: #ff0000">3）new/delete的使用除了分配内存和释放，还调用了类型的构造函数和析构函数，而malloc/free只是简单的分配和释放内存。</SPAN></P>
<P>二 数组与指针</P>
<P>C++的数组经常需要和指针来结合使用，下面来进行相关的强化训练。实例如下：</P>
<P>&nbsp;</P>
<DIV class=cnblogs_code><IMG id=Code_Closed_Image_153047 style="DISPLAY: none" 
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width=11 align=top><IMG id=Code_Open_Image_153047 
onclick="this.style.display='none'; document.getElementById('Code_Open_Text_153047').style.display='none'; getElementById('Code_Closed_Image_153047').style.display='inline'; getElementById('Code_Closed_Text_153047').style.display='inline';" 
height=16 
src="[C++对象模型][3]指针与数组 - iTech's Blog - 博客园.files/ExpandedBlockStart.gif" 
width=11 align=top><SPAN class=cnblogs_code_Collapse 
id=Code_Closed_Text_153047>Code</SPAN><SPAN id=Code_Open_Text_153047><BR><!--<br /><br />Code highlighting produced by Actipro CodeHighlighter (freeware)<br />http://www.CodeHighlighter.com/<br /><br />--><SPAN 
style="COLOR: #0000ff">#pragma</SPAN><SPAN 
style="COLOR: #000000">&nbsp;once</SPAN><SPAN 
style="COLOR: #000000"><BR>#include&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;</SPAN><SPAN 
style="COLOR: #000000">iostream</SPAN><SPAN 
style="COLOR: #000000">&gt;</SPAN><SPAN style="COLOR: #000000"><BR></SPAN><SPAN 
style="COLOR: #0000ff">using</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">namespace</SPAN><SPAN 
style="COLOR: #000000">&nbsp;std;<BR><BR></SPAN><SPAN 
style="COLOR: #0000ff">void</SPAN><SPAN 
style="COLOR: #000000">&nbsp;PrintArray(</SPAN><SPAN 
style="COLOR: #0000ff">double</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">*</SPAN><SPAN 
style="COLOR: #000000">p,&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">int</SPAN><SPAN 
style="COLOR: #000000">&nbsp;num)<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">for</SPAN><SPAN style="COLOR: #000000">(</SPAN><SPAN 
style="COLOR: #0000ff">int</SPAN><SPAN 
style="COLOR: #000000">&nbsp;i&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">0</SPAN><SPAN 
style="COLOR: #000000">;&nbsp;i&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;num;&nbsp;</SPAN><SPAN 
style="COLOR: #000000">++</SPAN><SPAN 
style="COLOR: #000000">i)<BR>&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cout&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;p[i]&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;}<BR>&nbsp;&nbsp;&nbsp;&nbsp;cout&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;endl&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">The&nbsp;array&nbsp;is&nbsp;end!</SPAN><SPAN 
style="COLOR: #800000">"</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;endl;<BR>}<BR></SPAN><SPAN 
style="COLOR: #0000ff">void</SPAN><SPAN 
style="COLOR: #000000">&nbsp;PrintArray(</SPAN><SPAN 
style="COLOR: #0000ff">double</SPAN><SPAN 
style="COLOR: #000000">&nbsp;arr[</SPAN><SPAN 
style="COLOR: #800080">3</SPAN><SPAN 
style="COLOR: #000000">])&nbsp;<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">for</SPAN><SPAN style="COLOR: #000000">(</SPAN><SPAN 
style="COLOR: #0000ff">int</SPAN><SPAN 
style="COLOR: #000000">&nbsp;i&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">0</SPAN><SPAN 
style="COLOR: #000000">;&nbsp;i&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800080">3</SPAN><SPAN 
style="COLOR: #000000">;&nbsp;</SPAN><SPAN style="COLOR: #000000">++</SPAN><SPAN 
style="COLOR: #000000">i)<BR>&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cout&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #000000">*</SPAN><SPAN 
style="COLOR: #000000">(arr</SPAN><SPAN style="COLOR: #000000">+</SPAN><SPAN 
style="COLOR: #000000">i)</SPAN><SPAN style="COLOR: #008000">/*</SPAN><SPAN 
style="COLOR: #008000">arr[i]</SPAN><SPAN style="COLOR: #008000">*/</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;}<BR>&nbsp;&nbsp;&nbsp;&nbsp;cout&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;endl&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">The&nbsp;array&nbsp;is&nbsp;end!</SPAN><SPAN 
style="COLOR: #800000">"</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;endl;<BR>}<BR></SPAN><SPAN 
style="COLOR: #0000ff">void</SPAN><SPAN 
style="COLOR: #000000">&nbsp;ChangeArray(</SPAN><SPAN 
style="COLOR: #0000ff">double</SPAN><SPAN 
style="COLOR: #000000">&nbsp;arr[</SPAN><SPAN 
style="COLOR: #800080">3</SPAN><SPAN style="COLOR: #000000">])&nbsp;</SPAN><SPAN 
style="COLOR: #008000">//</SPAN><SPAN 
style="COLOR: #008000">&nbsp;数组传参为传指针，所以函数内可以修改</SPAN><SPAN 
style="COLOR: #008000"><BR></SPAN><SPAN 
style="COLOR: #000000">{<BR>&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">for</SPAN><SPAN style="COLOR: #000000">(</SPAN><SPAN 
style="COLOR: #0000ff">int</SPAN><SPAN 
style="COLOR: #000000">&nbsp;i&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">0</SPAN><SPAN 
style="COLOR: #000000">;&nbsp;i&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800080">3</SPAN><SPAN 
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style="COLOR: #000000">i)<BR>&nbsp;&nbsp;&nbsp;&nbsp;{<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;arr[i]&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">10</SPAN><SPAN 
style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;}<BR>}<BR></SPAN><SPAN 
style="COLOR: #0000ff">void</SPAN><SPAN 
style="COLOR: #000000">&nbsp;PrintArray(</SPAN><SPAN 
style="COLOR: #0000ff">double</SPAN><SPAN 
style="COLOR: #000000">&nbsp;arr[</SPAN><SPAN 
style="COLOR: #800080">3</SPAN><SPAN style="COLOR: #000000">][</SPAN><SPAN 
style="COLOR: #800080">3</SPAN><SPAN 
style="COLOR: #000000">])<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">for</SPAN><SPAN style="COLOR: #000000">(</SPAN><SPAN 
style="COLOR: #0000ff">int</SPAN><SPAN 
style="COLOR: #000000">&nbsp;i&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">0</SPAN><SPAN 
style="COLOR: #000000">;&nbsp;i&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800080">3</SPAN><SPAN 
style="COLOR: #000000">;&nbsp;</SPAN><SPAN style="COLOR: #000000">++</SPAN><SPAN 
style="COLOR: #000000">i)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">for</SPAN><SPAN style="COLOR: #000000">(</SPAN><SPAN 
style="COLOR: #0000ff">int</SPAN><SPAN 
style="COLOR: #000000">&nbsp;j&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">0</SPAN><SPAN 
style="COLOR: #000000">;&nbsp;j&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800080">3</SPAN><SPAN 
style="COLOR: #000000">;&nbsp;</SPAN><SPAN style="COLOR: #000000">++</SPAN><SPAN 
style="COLOR: #000000">j)<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;cout&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;arr[i][j]&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;cout&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;endl&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800000">"</SPAN><SPAN 
style="COLOR: #800000">The&nbsp;array&nbsp;is&nbsp;end!</SPAN><SPAN 
style="COLOR: #800000">"</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #000000">&lt;&lt;</SPAN><SPAN 
style="COLOR: #000000">&nbsp;endl;<BR>}<BR><BR></SPAN><SPAN 
style="COLOR: #0000ff">int</SPAN><SPAN 
style="COLOR: #000000">&nbsp;GetLength(){</SPAN><SPAN 
style="COLOR: #0000ff">return</SPAN><SPAN 
style="COLOR: #000000">&nbsp;</SPAN><SPAN style="COLOR: #800080">3</SPAN><SPAN 
style="COLOR: #000000">;}<BR><BR></SPAN><SPAN 
style="COLOR: #0000ff">void</SPAN><SPAN 
style="COLOR: #000000">&nbsp;TestArray()<BR>{<BR>&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN 
style="COLOR: #008000">//</SPAN><SPAN 
style="COLOR: #008000">&nbsp;数组的定义和初始化</SPAN><SPAN 
style="COLOR: #008000"><BR></SPAN><SPAN 
style="COLOR: #000000">&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">short</SPAN><SPAN 
style="COLOR: #000000">&nbsp;months[</SPAN><SPAN 
style="COLOR: #800080">12</SPAN><SPAN style="COLOR: #000000">]&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;{</SPAN><SPAN 
style="COLOR: #800080">31</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">28</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">31</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">30</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">31</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">30</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">31</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">31</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">30</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">31</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">30</SPAN><SPAN style="COLOR: #000000">,</SPAN><SPAN 
style="COLOR: #800080">31</SPAN><SPAN 
style="COLOR: #000000">};<BR>&nbsp;&nbsp;&nbsp;&nbsp;</SPAN><SPAN 
style="COLOR: #0000ff">double</SPAN><SPAN 
style="COLOR: #000000">&nbsp;arr[</SPAN><SPAN 
style="COLOR: #800080">3</SPAN><SPAN 
style="COLOR: #000000">];&nbsp;<BR>&nbsp;&nbsp;&nbsp;&nbsp;arr[</SPAN><SPAN 
style="COLOR: #800080">0</SPAN><SPAN style="COLOR: #000000">]&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">1.0</SPAN><SPAN 
style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;arr[</SPAN><SPAN 
style="COLOR: #800080">1</SPAN><SPAN style="COLOR: #000000">]&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">2.0</SPAN><SPAN 
style="COLOR: #000000">;<BR>&nbsp;&nbsp;&nbsp;&nbsp;arr[</SPAN><SPAN 
style="COLOR: #800080">2</SPAN><SPAN style="COLOR: #000000">]&nbsp;</SPAN><SPAN 
style="COLOR: #000000">=</SPAN><SPAN style="COLOR: #000000">&nbsp;</SPAN><SPAN 
style="COLOR: #800080">3.0</SPAN><SPAN
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