# Include & lt; iostream & gt; and # include & lt; iostream.

 

In the new C ++ standard, the method to generate a new header file is to remove. h from the existing C ++ header file name. For example, <iostream. h> is changed to <iostream>, <complex. h> is changed to <complex>. Use the same method for the C header file, but add a c before each name. Therefore, <string. h> of C is changed to <cstring>, <stdio. h> is changed to <cstdio>, and so on.

 

The old C ++ header file is officially opposed to use (specifically, it is not supported), but the old C header file is not (to maintain compatibility with C ).

 

The following is the current situation of the C ++ header file:

 

· The old C ++ header file names, such as <iostream. h>, will continue to be supported, even though they are not in the official standard. The contents of these header files are not in the namespace std.

 

· The New C ++ header file contains the same basic functions as the corresponding old header file, but the header file contains the content in the namespace std. (Some details of the library are modified during the standardization process, so the old header file and the object in the new header file do not necessarily correspond completely .)

 

· The Standard C header file is supported, as shown in <stdio. h>. The header file is not in std.

 

· The New C ++ header file with the C library function has a name such as <cstdio>. They provide the same content as the corresponding old C header file, but the content is in std

 

From youhaoxinqin's column