What is the data type of macro in C?

What is the data type of macro in C?

In C, function-like macros are much similar to a function call. In this type of macro, you can define a function with arguments passed into it. TechVidvan Tutorial: Macros with arguments! In the above example, the compiler finds the name of the macro (AREA(a)) and replaces it with the statement (a*a).

What is macro data type?

Macros are purely text replacement and expansion. They have nothing to do with variable types or memory. Also, the statements are incorrect– 0 is neither positive nor negative.

What is __ Va_opt __?

In C++20, the preprocessor supports __VA_OPT__ as a way to optionally expand tokens in a variadic macro if the number of arguments is greater than zero. Clang SVN has implemented this feature, but they haven’t added a feature test macro for it.

Where is __ Va_args __ defined?

The C standard mandates that the only place the identifier __VA_ARGS__ can appear is in the replacement list of a variadic macro. It may not be used as a macro name, macro argument name, or within a different type of macro. It may also be forbidden in open text; the standard is ambiguous.

What is macro in embedded C?

A macro is a fragment of code which has been given a name. Whenever the name is used, it is replaced by the contents of the macro. There are two kinds of macros. You may define any valid identifier as a macro, even if it is a C keyword. The preprocessor does not know anything about keywords.

How does macro work in C?

Macros and its types in C/C++ A macro is a piece of code in a program that is replaced by the value of the macro. Macro is defined by #define directive. Whenever a macro name is encountered by the compiler, it replaces the name with the definition of the macro.

Why do we use macros in C?

The Concept of C Macros Macros are generally used to define constant values that are being used repeatedly in program. Macros can even accept arguments and such macros are known as function-like macros. It can be useful if tokens are concatenated into code to simplify some complex declarations.

How #define works in C?

In the C Programming Language, the #define directive allows the definition of macros within your source code. These macro definitions allow constant values to be declared for use throughout your code. You generally use this syntax when creating constants that represent numbers, strings or expressions.

What is macro expansion C++?

If the macro accepts arguments, the actual arguments following the macro name are substituted for formal parameters in the macro body. The process of replacing a macro call with the processed copy of the body is called expansion of the macro call. In practical terms, there are two types of macros.

What is Variadic function in C?

Variadic functions are functions (e.g. printf) which take a variable number of arguments. The declaration of a variadic function uses an ellipsis as the last parameter, e.g. int printf(const char* format.);. See variadic arguments for additional detail on the syntax and automatic argument conversions.

What is macro substitution in C?

The macro substitution is a process where an identifier in a program is replaced by a predefined string or a value. Different forms of macro substitution: 1. Simple macro substitution.

What is macro in C++ with example?

Macros and its types in C/C++. A macro is a piece of code in a program that is replaced by the value of the macro. Macro is defined by #define directive. Whenever a micro name is encountered by the compiler, it replaces the name with the definition of the macro.

How many types of macros are there in C?

There are two types of macros: object- like macro when data objects are used and function-like macro when function calls are used. Examples of Macros in C A macro in C programming language is a block or set of statements of program code that can be replaced by macro #define directive. As discussed above there are two types of macros.

How do you use a macro name with a value?

This macro can be a pointer variable or identifier or variable defined using #define and it is replaced by its value. This is mainly used when numeric constants are required. In this example, we can use “MAX” as a macro name with value 100 which will be replaced with “MAX”.

What is the symbol for macro in C?

These macros always start with symbol “#” and the statements staring with this symbol are invoked by the compiler. There are two types of macros: object- like macro when data objects are used and function-like macro when function calls are used.