Pointers as function Arguments

Pointers as function Arguments:

      Arguments can be passed to a function in 2 ways.

(i)                             call by value and

(ii)                           call by reference

v  In call by value, we pass values of actual arguments to the corresponding formal arguments. The changes in formal arguments do not reflect in actual arguments.

v  In call by reference, addresses of actual arguments are passed from calling function to the called function. The formal arguments that receive addresses are declared as pointers variable of same datatype. Here, the changes that are made in formal arguments are reflected in the actual arguments also.

 A Program to find the bigger of two numbers using pointers as function arguments.

#include<stdio.h>

#include<conio.h>

int large(int *, int *);

void main()

{

      int x,y,z;

      printf(“\n enter any 2 values”);

      scanf(“%d%d”,&x,&y);

      z=large(&x,&y);

      printf(“biggest=%d”,z);

}

int large(int *p, int *q)

{

      if(*p>*q)

      return (*p)

      else

      return (*q);

}

 A Program to print the array elements using pointers as function arguments.

#include<stdio.h>

#include<conio.h>

void array(int *);

void main()

{

int a[5]={1,2,3,4,5};

clrscr();

array(a);

}

void array(int *x)

{

int i;

for(i=0;i<5;i++)

{

printf(“%d”,*x);

x++;

}

}