getline（）

Get line from stream into string

  • Extracts characters from is and stores them into str until the delimitation character delim is found (or the newline character, ‘\n’, for (2)).

从is中提取字符并将其存储到str中，直到找到分隔符delim（或**换行符’\n’**，for（2））。

  • The extraction also stops if the end of file is reached in is or if some other error occurs during the input operation.

如果在中到达文件结尾，或者在输入操作期间发生其他错误，提取也会停止。

  • If the delimiter is found, it is extracted and discarded (i.e. it is not stored and the next input operation will begin after it).

如果找到分隔符，则会将其提取并丢弃（即不存储它，然后将开始下一个输入操作）。

  • Note that any content in str before the call is replaced by the newly extracted sequence.
    Each extracted character is appended to the string as if its member push_back was called.

请注意，调用之前str中的任何内容都将被新提取的序列替换。
每个提取的字符都附加到字符串中，就好像调用了其成员push_back一样。

指针

注意点

  1. 使用指针开辟数组时，一定要在使用前初始化值
  2. 使用指针才能够开辟动态数组，但是不太容易得到数组的长度