Function Pointer Examples

functionPointerExamples.c

/*
 * 	FUNCTION POINTERS
 * 	Created By		:Sinan NAR
 * 	Creation Date	        :26/02/2012
 *
 *      you can ask me anything about these codes if you do not understand
 *      mail me : sinan.nar@gmail.com
 */

#include <stdio.h>

/*
 * Using function pointer in struct
 * We need to forwarddeclaration of this struct cause of fnction 
 * prototype of func7
 */
typedef struct structExmp;	//forward decleration

void func7(structExmp);		//function prototype

typedef struct{				//struct decleration
	int num;
	void (*printfNum1)(structExmp) ;
}structExmp;

/* FUNCTION PROTOTYPES */
void func1(int);
void func2(int,int);
void func3(int);
void func4(char);
void func5(char,char);
char* func6(int,char*);



/* MAIN */
int main(void)
{
	/* FUNCTION POINTERS DECLERATIONS */
	void (*funcPtr1)(int);
	void (*funcPtr2)(int,int);
	void (*funcPtr3)(char);
	void (*funcPtr4)(char,char);
	char* (*funcPtr5)(int,char*);
	
	/*	STRUCT DECLERATION*/
	structExmp x;
	
	/*	INITIALIZATION */
	x.printfNum1=func7;
	x.num=2;
	
	funcPtr1=func1;
	funcPtr2=func2;
	funcPtr3=func4;
	funcPtr4=func5;
	funcPtr5=func6;
	
	/* Function calls and tests */
	funcPtr1(1);
	funcPtr1=func3;
	funcPtr1(2);
	funcPtr2(1,2);
	funcPtr3('a');
	funcPtr4('a','b');
	funcPtr5(5,"sinan");
	
	/* Struct test */
	x.printfNum1();
	

	return 0;
}

/* FUNCTION DECLERATIONS */

void func1(int num1)
{
	printf("func1 called and print %d on screen\n",num1);
}

void func2(int num1,int num2)
{
	printf("func2 called and print %d and %d on screen\n",num1,num2);
}

void func3(int num1)
{
	printf("func3 called and print %d on screen\n",num1);
}


void func4(char var1)
{
	printf("func4 called and print %c on screen\n",var1);
}

void func5(char var1,char var2)
{
	printf("func5 called and print %c and %c on screen\n",var1,var2);
}


char* func6(int num1,char* word1)
{
	printf("func6 called and print %d and %s on screen\n",num1,word1);
	return word1;
}

void func7(structExmp var)
{
	printf("func7 called and print %d on screen\n",var.num);
}