What is Functions explain with example

What is Functions explain with example.

C provides functions which are again similar most languages. One difference is that C regards main() as function. Also unlike some languages, such as Pascal, C does not have procedures -- it uses functions to service both requirements.
Let us remind ourselves of the form of a function:

  returntype fn_name(1, parameterdef2, )

               

                {

                 localvariables

                 functioncode

                 }
Let us look at an example to find the average of two integers:

  float findaverage(float a, float b)
                { float average;

>                 average=(a+b)/2;
                         return(average);
                }

We would call the function as follows:

         main()
                {          float a=5,b=15,result;

                         result=findaverage(a,b);
                         printf("average=%f n",result);
                }

Note: The return statement passes the result back to the main program.