A program in C Language which uses two parameters as input and returns the result of any one of the four basic math operations. This is decided with a char and a function pointer is returned to be used in the main function.

return_a_function_pointer.c

#include <stdio.h>

typedef float (*pt2Func)(float, float);

float Plus	(float a, float b)	{ return a+b; }
float Minus	(float a, float b)	{ return a-b; }
float Multiply	(float a, float b)	{ return a*b; }
float Divide	(float a, float b)	{ return a/b; }

pt2Func GetPtr2 (const char opCode)
{
	if (opCode == '+') return &Plus;
	if (opCode == '-') return &Minus;
	if (opCode == '*') return &Multiply;
	if (opCode == '/') return &Divide;
}

float (*GetPtr1 (const char opCode))(float, float)
{
	if (opCode == '+') return &Plus;
	if (opCode == '-') return &Minus;
	if (opCode == '*') return &Multiply;
	if (opCode == '/') return &Divide;
}

void Return_A_Function_Pointer (void)
{
	/* define a function pointer */
	float (*pt2Function) (float, float);

	pt2Function = GetPtr1 ('+');
	printf ("%03.1f\n", pt2Function (1.2, 3.4));
	pt2Function = GetPtr2 ('-');
	printf ("%03.1f\n", pt2Function (1.2, 3.4));
}

int main (void)
{
	Return_A_Function_Pointer();

	return 0;
}