c++文件流基本用法(fstream, ifstream, ostream)

<ol><li class="li1"><div class="de1"><span class="co2">#include <fstream.h></span></div></li><li class="li1"><div class="de1"> </div></li><li class="li1"><div class="de1"><span class="kw4">void</span> main</div></li><li class="li1"><div class="de1"><span class="br0">{</span></div></li><li class="li2"><div class="de2">ofstream <span class="kw4">file</span>;</div></li><li class="li1"><div class="de1"> </div></li><li class="li1"><div class="de1"><span class="kw4">file</span>.<span class="me1">open</span><span class="br0">(</span><span class="st0">"file.txt"</span><span class="br0">)</span>;</div></li><li class="li1"><div class="de1"> </div></li><li class="li1"><div class="de1">file<<<span class="st0">"Hello file<span class="es0">/n</span>"</span><<<span class="nu0">75</span>;</div></li><li class="li2"><div class="de2"> </div></li><li class="li1"><div class="de1"><span class="kw4">file</span>.<span class="me1">close</span><span class="br0">(</span><span class="br0">)</span>;</div></li><li class="li1"><div class="de1"><span class="br0">}</span></div></li></ol><ol><li class="li1"><div class="de1"><span class="