fopen中r+和w+的区别是什么？

Question

如题所述

Answer 1

r+: Open for reading and writing.  The stream is positioned  at  the beginning of the file.


w+:Open for reading and writing.  The file is created  if  it  does not  exist, otherwise it is truncated.  The stream is positioned at the beginning of the file.


r+具有读写属性，从文件头开始写，保留原文件中没有被覆盖的内容；


w+具有读写属性，写的时候如果文件存在，会被清空，从头开始写。