NULL Pointers in C/C++ | C++ Language | Coding Winds

NULL Pointer

Hello people, today we are going to read about the null pointers used in C/C++. Why are we using them? What is it’s significance? What we actually gonna gain by typing ‘NULL’ in our code? These are the questions which crosses the mind of every programmer. But the amount of attention given to these questions is very less, and the importance of getting the answers of these questions is far more important.

Just like normal variables, pointers are not initialized when they are declared. Unless a value is assigned, a pointer will point to some garbage address by default.

Besides memory addresses, there is one additional value that a pointer can hold: a null value. A null value is a special value that means the pointer is not pointing at anything. A pointer holding a NULL value is called a null pointer.

So, we initialize a pointer variable with NULL pointer when we don’t want to assign the memory to the variable pointer.

For example,

int *ptr = NULL;

this implies that the variable pointer ‘ptr’ is not assigned value yet.

Initialising our pointer with the NULL pointer if not giving them any other value is considered to be among good practices.

A null pointer should not be confused with an uninitialized pointer: a null pointer is guaranteed to compare unequal to any pointer that points to a valid object. However, depending on the language and implementation, an uninitialized pointer may not have any such guarantee. It might compare equal to other, valid pointers; or it might compare equal to null pointers. It might do both at different times. Or the comparison might be undefined behaviour.

 

So this is all about ‘NULL’ pointer, thank you for giving it a read.

If you still have any doubt on this topic then do come to us via email "sophomoretechs@gmail.com" or via instagram "@coding.winds".

We also have an article on space complexity, give it a read by clicking here.