- What are the uses of NULL pointer and void pointer.
- Can pointer arithmetic be applied to void pointers.
- What is pointer Arithmetic ? What are the valid and Invalid Pointer Arithmetic operations.
What are the uses of NULL pointer and Void pointer
NULL pointer is used to initialize a pointer at the time of declaration if we don’t have any explicit value to initialize. It is a good practice to initialize a pointer with NULL to ensure that it is not pointing a random memory location.
A Void pointer is used to point to a variable of any data type. It is a generic pointer, before accessing the data stored at the location pointed by a void pointer we have to typecast it to some particular pointer type.
Can pointer arithmetic be applied to Void pointers
NO, pointer arithmetic cannot be applied to a void pointer because it is a generic pointer, compiler is unaware about the type of data it is pointing to like whether it is char, float or structure.
For Example:
When a character pointer is incremented, its value is increased by 1 that is equal to the size of char data type. A void pointer can point to a variable of any data type of size X, So while incrementing a void pointer compiler don’t know how much value to add to current address.
What is pointer Arithmetic ? What are the valid and Invalid Pointer Arithmetic operations.
We can perform arithmetic operations on pointer variable just as you can on numeric value. A pointer in C is a variable which is used to store the memory address which in turn is a numeric value. The arithmetic operations on pointer variable effects the memory address pointed by pointer.
Valid Pointer Arithmetic Operations
- Adding a number to pointer.
- Subtracting a number form a pointer.
- Incrementing a pointer.
- Decrementing a pointer.
- Subtracting two pointers.
- Comparison on two pointers.
Invalid Pointer Arithmetic Operations
- Addition of two pointers.
- Division of two pointers.
- Multiplication of two pointers.