Compile Header Log For Free

The first was to enclose the name of the header file in double quotes, e.g. "header. h" . In this case, the compiler should (typically) look for the header in the same directory as the source file.

This question is generally asked in interviews to confuse the candidate and also to test the knowledge of the student in C programming. So, in short, the answer is yes. We can compile C program without header file. But how?

Header files are not compiled directly, Instead, header files are included into other source files via #include . In fact, when you invoke a C/C++ compiler, before the ?real? compiler starts, it runs a pre-processor whose job is to handle the special instructions that begin with # .

Header files cannot be replaced at runtime, since they are evaluated at the first step of the compilation of the source code to a fixed binary. What you are looking for is the factory pattern. Create a (pure virtual) interface class ICD . This should contain all common data and member functions.

Header-only libraries do not need to be separately compiled, packaged and installed in order to be used. All that is required is to point the compiler at the location of the headers, and then #include the header files into the application source.

GCC looks for headers requested with #include " file " first in the directory containing the current file, then in the directories as specified by -iquote options, then in the same places it would have looked for a header requested with angle brackets.

In C++ programming, it's common practice to separate class interface information into header files. These header files can later be included in programs that use the class. By precompiling these headers, you can reduce the time a program takes to compile.

Most standard headers are stored in /usr/include .

Only source files are passed to the compiler (to preprocess and compile it). Header files aren't passed to the compiler.

You don't need to compile header files. It doesn't actually do anything, so there's no point in trying to run it. However, it is a great way to check for typos and mistakes and bugs, so it'll be easier later.