Can we define macro inside main function?

You can use it inside a function, but it is not scoped to the function. So, in your example, the second definitions of a macro will be a redefinition and generate an error. You need to use #undef to clear them first.

What are preprocessor statements?

Preprocessor statements are handled by the compiler (or preprocessor) before the program is actually compiled. All # statements are processed first, and the symbols (like TRUE) which occur in the C program are replaced by their value (like 1).

Can define be used inside main?

Originally Answered: In C language we can define a macros inside main function? Yes. When you feed your source code to the compiler, it is first subjected to a preprocessor.

What are the preprocessor directives or statements?

Preprocessor directives, such as #define and #ifdef , are typically used to make source programs easy to change and easy to compile in different execution environments. Directives in the source file tell the preprocessor to take specific actions.

Is it better to use macro or function?

Macros are typically faster than functions as they don’t involve actual function call overhead….Conclusion:

Which statement is not true about preprocessor directives in C?

Preprocessor directives have to end with a semicolon(;) is not true statement about the directives. Preprocessor directives are lines included in a program that being with the character #, processed by a preprocessor and form an integral part of the code.

What are the functions of preprocessor?

In computer science, a preprocessor (or precompiler) is a program that processes its input data to produce output that is used as input to another program. The output is said to be a preprocessed form of the input data, which is often used by some subsequent programs like compilers.

What is preprocessor explain any four preprocessor?

As the name suggests Preprocessors are programs that process our source code before compilation. There are a number of steps involved between writing a program and executing a program in C / C++. This file is then processed by preprocessors and an expanded source code file is generated named program.

How does main differ from other user-defined function?

The main() function is just a regular user-defined function — but it has two special properties: In a hosted implementation (the normal type), it is the function called by the start-up code. In C99 and later, if execution falls off the end of main() without an explicit return statement, it is equivalent to return 0; .

Which of the following statement is not true about preprocessor directives?

Which pre processor does not belong to conditional compilation?

17) What is the file extension of expanded source code of . C file after preprocessing.? Explanation: def….Some good C Books.

How does preprocessor work in C programming?

Preprocessor will first search for the system file ‘stdio.h’ in the standard directory of C header files and once found will include all the code of that file in the current source file before moving forward to the code of print statement in the above code.

How do you use preprocessor features?

Most preprocessor features are active only if you use preprocessing directives to request their use. Preprocessing directives are lines in your program that start with `#’ . The `#’ is followed by an identifier that is the directive name . For example, `#define’ is the directive that defines a macro.

What does the ‘#’ symbol indicate in a preprocessor program?

The ‘#’ symbol indicates that, whatever statement starts with #, is going to the preprocessor program, and preprocessor program will execute this statement.

What are the preprocessor directives in C?

C preprocessor directives – #include, #define, #undef and conditional directives. A C preprocessor is a statement substitution (text substitution) in C programming language. It instructs the C compiler to do some specific (required) pre-processing before the compilation process.