Compilation error: the header file is included, but the prompt class is not declared (the header file contains each other)

Environment:

Ubuntu 11.10g ++

Error:

Compile a header fileCode(A. H contains B. H, B. H contains a. h)

However, an error occurs during compilation. The prompt is: Class B is not declared in the. h file; Class A is not declared in the B. H file.

Error analysis:

# Include <> has been used in the header file to introduce the header file of the other party.

At the beginning, I thought there was a name error and I was checking it.

If no input error is found, encoding is required.

I have encountered similar problems when the header files contain each other before, but it takes too long to forget...

Solution:

Declare Class B in A. H file

Add the following statement before defining Class:

Class B;

Similarly, the same operation is performed in B. H.