7. What Do #include and #define Mean?
They’re Preprocessor Directives
Two types of lines you see in many C programs are not C commands at all. They are preprocessor directives. A preprocessor directive always begins with a pound sign (#). Preprocessor directives don’t cause anything to happen at runtime (when you run your program). Instead, they do work during the compiling of your program.
The most often-used preprocessor directives are
• #include
• #define
In earlier chapters, you saw examples that used #include. This chapter finally takes the ...
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