EXAMPLE OF PASS  BY REFERENCE
#include<stdio.h>
/* function prototype - the middle argument is the pointer */
void fun1(int,int*,char);
/* function prototype - the 1st & 3rd arguments are pointers */
void fun2(int*,int,char*);
int main()
{
/* declare variables */
int num1, num2;
char ch;
				Variable Values at Initialization
/*initialize variables */				num1	10
num1=10;				num2	15
num2=15;				ch	A
ch='A';
/* fun1 is called */
				Variable Values after return from fun1
fun1(num1, &num2, ch);				num1	10
				num2	30
/* Notice only num2 changed */				ch	A
/* This is because it's a call by reference */
/*fun2 is called */
				Variable Values after return from fun2
fun2(&num1,num2,&ch);				num1	11
				num2	30
/* This time only num1 and ch changed */				ch	G
/* because their addresses were passed */
/* to the function */
return 0;
} /* end of function main */
void fun1(int a, int *b, char v)
{
/* num1's value is passed to fun1 and */
/* stored in a.  num2's address is passed to */
/* fun1 where it is refered to as b,  */
/* any change here is reflected back in main */
/* ch's value is also passed to fun1 and */
/* stored in v.  one is a local variable to fun1 */
/* and is known only in fun1 */
int one;
one=a;				Variable Values at the end of fun1
a++;				a	11
*b=*b * 2;				*b	30
v='B';				v	B
}				one	10
/* end of fun1 *;
void fun2(int *x, int y, char *w)
{
/* x is a pointer to num1 in main */
/* y is passed the value from num2 in main */
/* w is a pointer to ch in main */
*x=*x+1;				Variable Values at the end of fun2
y*=2;				*x	11
*w='G';				y	60
}				*w	G
/* end of fun2 */
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