#Macro definition in c code#

Now, this replacement of value occurs due to the preprocessor and preprocessor directive #define. Here macro name PI at the 11th line got replaced with the macro value 3.14 as we saw in the definition, and we got the area of a circle as the output. We defined the PI constant as a macro with the value 3.14.

#Macro definition in c code#

In the above code example, we wrote a program to calculate the area of a circle with the help of a given radius.

We will take a deeper look at what preprocessor directive is in the later part of this article, but first, let's try to understand macro with the help of code example- Code: The syntax of the macro is as shown in the following figure. Whenever the compiler encounters the macro, it replaces the macro name with the macro value. Macro is just a name given to certain values or expressions it doesn't point to any memory location. The macro is defined with the help of #define preprocessor directive and the macro doesn’t end with a semicolon( ).

The macro in C language is known as the piece of code which can be replaced by the macro value. In this article, we will explore the use of macros in C language, their different types and use cases. Macros are one of the convenient ways to write robust and scalable code. Suppose we are working on an application in C language and there is one value or an object or segment of code which we require so many times in our code then with the help of macros we can define it once and use it many times. Macros have multiple types and there are some predefined macros as well. Macros in C are very useful at multiple places to replace the piece of code with a single value of the macro. Macro in C programming is known as the piece of code defined with the help of the #define directive.