title: Why putchar('\\\'); won't work
body: <p>I want to get the output <code>\\</code> ,so I type this to my code    <code>putchar('\\\');</code>
  but it doesn't work out ,and I get the following error</p>
  
  <blockquote>
    <p>D:\c++ work\change\change.cpp(17) : error C2001: newline in constant<br>
    D:\c++ work\change\change.cpp(17) : fatal error C1057: unexpected end of file in macro expansion</p>
  </blockquote>
  
  <p>why? </p>