15周《C++语言基础》程序阅读——二进制文件及文件的随机读写（1）

标签：c++   编程   iostream   计算机   namespace   

1、阅读并运行下面的两个程序，分别用记事本和二进制文件阅读器（请自行下载Binary Viewer等程序，或者用DOS中的Debug程序，并百度其用法）。查看其内容，并理解文件存储的原理。

（1）

<code class="hljs cpp has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#include <iostream></span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#include <fstream></span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#include <cstdlib></span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">using</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">namespace</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">std</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> main( )
{
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> a;
    ofstream outfile(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"f1.dat"</span>,ios::out);
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>(!outfile)      
    {
        <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">cerr</span><<<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"open error!"</span><<endl;
        <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">exit</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>);
    }
    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">cin</span>>>a;
    outfile<<a<<endl;
    outfile.close();   
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li></ul>

（2）

<code class="hljs cpp has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#include <iostream></span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#include <fstream></span>
<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">#include <cstdlib></span>
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">using</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">namespace</span> <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">std</span>;
<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> main( )
{
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> a;
    ofstream outfile(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"f2.dat"</span>,ios::out|ios::binary);
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span>(!outfile)
    {
        <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">cerr</span><<<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"open error!"</span><<endl;
        <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">exit</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>);
    }
    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">cin</span>>>a;
    outfile.write((<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">char</span>*)&a, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">sizeof</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span>));
    outfile.close();
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;
}
<img src="http://img.blog.csdn.net/20150615215313984?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvenBfX193YWo=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast" alt="" /><img src="http://img.blog.csdn.net/20150615215313984?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvenBfX193YWo=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast" alt="" />
</code>

15周《C++语言基础》程序阅读——二进制文件及文件的随机读写（1）

标签：c++   编程   iostream   计算机   namespace   

原文地址：http://blog.csdn.net/zp___waj/article/details/46508461