# include < stdio.h>
void swap (int *, int *);
main ( )
{
int a=10, b=20;
swap(&a, &b); /* a,b are actual parameters */
printf (“a= %d \t b=%d ”, a ,b);
}
void swap (int *x , int *y) /* x, y are formal parameters */
{
int t;
t = *x;
*x=*y;
*y=t;
}
a=20 b= 10
# include < stdio.h>
# include < conio.h>
void copy (char *, char *);
main ()
{
char a[20], b[20];
printf (“ Enter string a:”);
gets(a);
printf (“ Enter string b:”);
gets(b);
printf (“ Before copy “ );
printf (“ a=%s and b=%s ”, a , b);
copy(a ,b);
printf (“After copy “);
printf (“ a=%s and b=%s”, a , b);
}
void copy (char *x, char *y)
{
int i=0;
while ((X[i]=Y[i]) != “\0‟)
i++;
}
Enter string a: computer
Enter string b: science
Before copy
a=computer and b= science
After copy
a=science and b=science