Self Doubt

Question

How far is Defining a function and macro related with each other?

Comments

https://www.geeksforgeeks.org/macros-vs-functions/

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@Srestha,Thank you so much.:)

Answer 1

macros are processed before the program is compiled and function are not processed but compiled.

Answer 2

• Macro is a preprocessor directive. Means macro is called before compilation started by a compiler . Macros are of two types 

1. Object like Macro-   #define NUMBERS
2. Funtion like Macro- Inline function i.e. #define foo()

• In the other side function can be created at the time Macro function call(as described before) and also can create without Macro function call.

Without Macro function call means it can create in compilation phase, and can create parse tree in the Lexical Analysis Phase i.e. 1st phase of a compiler

https://gateoverflow.in/166357/doubt

https://web.eecs.umich.edu/~prabal/teaching/eecs373-f11/readings/Preprocessor.pdf

https://www.slac.stanford.edu/comp/unix/gnu-info/cpp_1.html

https://www.slac.stanford.edu/comp/unix/gnu-info/m4_1.html

https://see.stanford.edu/Course/CS107/206

I think now how macro works will be clear

Comments

@Srestha,I have undergone thru the links mentioned,can you please tell me then what is the difference between initialization and macro definition?

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initialization int a=10;

but macro is done before main() called #define a 10

https://www.includehelp.com/c/variable-initialization-in-c-programming-language.aspx

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@srestha mam,

Macro is just a one line definition

need not to be true always...

#define square(x) \

x=(x*x)

 

this is also a macro 

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@Devshree Dubey 

@Srestha,Here you've initialized the value of A ?

brother, A macro can't be initialized

a macro is read by the preprocessor and change the source code ( changing means replacing the macros only )