15 Week "C + + language Basics" program reading--random reading and writing of binary files and files (1)

1, read and run the following two programs, respectively, with Notepad and binary file reader (please download binary viewer and other programs, or DOS in the debug program, and Baidu usage). View its contents and understand how the file is stored.

(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&Gt;<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:borde R-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>;} </code>

15 Week C + + language Basics program Reading--random reading and writing of binary files and files (1)