A null pointer in the C programming language is a pointer that does not point to any memory location and hence does not include any variable addresses. The base address of the segment is all that is kept. This means that while the C null pointer’s value is Null, its type is void.

A Null pointer is a variable in the C programming language that has a value of zero or has an address that points to nothing

A null pointer is a pointer that does not point to any valid memory address. It is a special value that indicates the absence of a valid target or the absence of an object being referred to.

In the C programming language, a Null pointer is a variable with a value of zero or an address that refers to nothing.

To turn a variable into a null pointer, which is a predefined macro in C, use the keyword NULL.
A pointer that points nowhere is known as a null pointer.

The null pointer can be used, among other things, to initialize a pointer variable when it hasn’t yet been given a valid memory address.

When we don’t wish to give any valid memory addresses, we can pass a null pointer as an argument to a function.

A null pointer, often referred to as a null reference, is a special value that indicates that a pointer or reference variable does not point to any valid memory location. In programming languages that support pointers or references, such as C, C++, Java, and others, a null pointer is used to represent the absence of an object or the lack of a valid target for the pointer.

When a pointer or reference is assigned the value of null, it means that it does not point to any valid object or memory address. Dereferencing or accessing a null pointer typically results in a runtime error, such as a null pointer exception or segmentation fault, depending on the programming language.

Here’s an example in C++ to illustrate the concept of a null pointer:

<span class="hljs-type">int</span>* ptr = <span class="hljs-literal">nullptr</span>; <span class="hljs-comment">// Assigning nullptr (or NULL) to a pointer</span>


In the above code, ptr is a pointer to an integer, and it is initialized with the value nullptr, which represents a null pointer in C++. It means that ptr does not currently point to any valid memory location.

If you try to access the value pointed to by a null pointer or perform any operation that requires a valid memory address, you will encounter an error. For example:

<span class="hljs-type">int</span> x = *ptr; <span class="hljs-comment">// Dereferencing a null pointer, which results in an error</span>


Attempting to dereference a null pointer like in the above code would lead to undefined behavior, and the program may crash or exhibit unexpected behavior.

To avoid such errors, it’s important to ensure that pointers are properly initialized and point to valid memory locations before being used. Additionally, it’s a good practice to check if a pointer is null before dereferencing it, to handle such cases gracefully and avoid crashes or exceptions.