C supports a special kind of pointer known as void pointer.
It s a generic pointer means it can be used for storing
any type of pointer(int,float,char etc).We can reduce complexity
and number of pointer using void pointer.
We can declare a pointer as void as we declared any
other pointer.E.g-void *ptr;
Advantage:i)Intialistining any pointer of any type.
ii)No type casting is require while intializing.
iii)it s may useful when data type is unknown.
iv)We can assign a void pointer to another non void pointer.
Disadvantage:i)No arithmetic operation is not possible in void pointer.
Use of void pointer-
#include <stdio.h>
#include<conio.h>
void call(void *ptr); /*function prototype*/
void main()
{
float f=90.88;
int i=80;
void *vptr;
clrscr();
printf("
Before Vpointer(integer)=%d",i);
call(&i);
printf("
After Vpointer(integer)=%d",i);
printf("
Before Vpointer=%.2f",f);
call(&f);
printf("
After Vptr=%.2f",f);
getch();
return;
}
void call(void *ptr)
{
char ch;
printf("
Enter the data type(i=integer/f=float)?");
ch=tolower(getch());
if(ch== f )
{
printf("
Enter the value:");
scanf("%f",ptr);
}
else
{
printf("
Enter the value:");
scanf("%d",ptr);
}
}
In the above example a single function(name call) used for taking any type of data.
Here i only accept Float&Integer value.(But you can use any type of data by modifying the function)
But it has a problem i.e for taking any value I used a option e.g(for integer
you have to press i or f for float)as if i used %d in scanf then it only accept integer value or
if i used %f then it only accept only floating value.
Auther:Deepraj Majumdar
Add:kolkata,West Bengal
e-mail:deep05kol@yahoo.com
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