GeeksforGeeks
geeksforgeeks.org › c language › null-pointer-in-c
NULL Pointer in C - GeeksforGeeks
To check for a null pointer before accessing any pointer variable.
Published: January 10, 2025
a value indicating that a pointer does not refer to a valid object
Wikipedia
en.wikipedia.org › wiki › Null_pointer
Null pointer - Wikipedia
June 13, 2026 - In systems with a tagged architecture, ... fact, a possibly null pointer can be seen as a tagged pointer with a computed tag. Because a null pointer does not point to a meaningful object, an attempt to access the data stored at that (invalid) memory location may cause a run-time error ...
Checking for NULL pointer in C/C++ - Stack Overflow
They do not depend on the definition of the symbol NULL. They do not expose the opportunity for the accidental assignment. And they are clear and succinct. Edit: As SoapBox points out in a comment, they are compatible with C++ classes such as unique_ptr, shared_ptr, auto_ptr that are objects that act as pointers ... More on stackoverflow.com
c - Accessing NULL pointers - Stack Overflow
This is part of my code... and i have several major problems that im stuck on... ok most of the problem that i can see so far has been fixed... but im still lost on where to free the memory. this i... More on stackoverflow.com
Checking for null pointers when 0 is a valid address
Don't use MCUs designed by crazy people. More on reddit.com
56
33
October 17, 2023Why does my code give segmentation fault when trying to return NULL ?
Because that becomes printf("%s", NULL) which is a null pointer dereference, an illegal memory access. More on reddit.com
22
0
September 27, 2023What is a null pointer in C?
A null pointer in C is a pointer that does not point to any valid memory location and is assigned the value NULL.
wscubetech.com
wscubetech.com › resources › c-programming › null-pointer
Null Pointer in C Language (Uses, Best Practices, Examples)
What is the value of a null pointer in C?
The value is NULL, which is usually defined as ((void *)0) or 0, depending on the system.
wscubetech.com
wscubetech.com › resources › c-programming › null-pointer
Null Pointer in C Language (Uses, Best Practices, Examples)
What’s the size of a null pointer in C?
The size is the same as any other pointer of the same type (typically 4 bytes in 32-bit systems, 8 bytes in 64-bit).
wscubetech.com
wscubetech.com › resources › c-programming › null-pointer
Null Pointer in C Language (Uses, Best Practices, Examples)
04:13
C/C++: The NULL Pointer and Why It Matters - YouTube
03:56
Null Pointer in C with Example | C Programming Tutorials - YouTube
18:59
NULL Pointer | C Programming Tutorial - YouTube
02:07
Null Pointers In C Programming Language - YouTube
21:34
C_81 Null Pointer in C | C Programming Tutorials - YouTube
Understanding the Null Pointers - YouTube
Unstop
unstop.com › home › blog › null pointer in c | a detailed explanation with examples
Null Pointer In C | A Detailed Explanation With Examples
May 3, 2024 - We also use the pointer ptr to access the elements of the array at index position i, and the %d format specifier in the formatted string represents an integer value. The printf() statement with the newline escape sequence shifts the cursor to the next line. After using the allocated memory, we free it using free() function to release it back to the system. As mentioned before, a null pointer in C is a special pointer that does not point to any valid memory address.
Quora
quora.com › What-happens-when-we-try-to-access-a-null-pointer-in-C
What happens when we try to access a null pointer in C? - Quora
Answer (1 of 4): The standard says that accessing a NULL ptr is “undefined behavior”. Undefined behavior can be anything, including: * Nothing at all - continue running the program as if nothing happened * Crashing the application * Corrupting application data From Wikipedia we have this: ...
WsCube Tech
wscubetech.com › resources › c-programming › null-pointer
Null Pointer in C Language (Uses, Best Practices, Examples)
July 27, 2026 - Learn in this tutorial about the null pointer in C, including its syntax, uses, how to check it, best practices, and examples to write efficient programs.
TutorialsPoint
tutorialspoint.com › cprogramming › c_null_pointer.htm
NULL Pointer in C
To check for a null pointer before accessing any pointer variable so that we can perform error handling in pointer-related code.
EDUCBA
educba.com › home › software development › software development tutorials › c programming tutorial › null pointer in c
Null pointer in C | How Null pointer work in C with Examples
March 28, 2023 - Explanation: In the above-modified code, we assign a pointer_var to the “NULL” value and we check with the condition if the value of the pointer is null or not. In most of the operating system, codes or programs are not allowed to access any memory which has its address as 0 because the memory with address zero 0is only reserved by the operating system as it has special importance, which states that the pointer is not intended to point to any memory location that can be accessible.
Call: +917738666252
Address: Unit no. 202, Jay Antariksh Bldg, Makwana Road, Marol, Andheri (East),, 400059, Mumbai
GNU
gnu.org › software › c-intro-and-ref › manual › html_node › Null-Pointers.html
Null Pointers (GNU C Language Manual)
A pointer value can be null, which means it does not point to any object. The cleanest way to get a null pointer is by writing NULL, a standard macro defined in stddef.h. You can also do it by casting 0 to the desired pointer type, as in (char *) 0.
Scaler
scaler.com › home › topics › what is null pointer in c?
What is Null Pointer in C? - Scaler Topics
September 4, 2023 - Null indicates that the pointer is pointing to the first memory location. meaning that 0th location. At a high level, NULL is a null pointer that is implemented in C for a multitude of scenarios. To initialize a pointer variable when it hasn't been assigned a proper memory address yet. Before accessing any pointer variable, check for a null pointer.
Dot Net Tutorials
dotnettutorials.net › home › null pointer in c
Null Pointer in C Language with Examples - Dot Net Tutorials
November 16, 2023 - In C programming, a null pointer is a pointer that does not point to any valid memory location. It’s a special type of pointer used to indicate that it is not intended to point to an accessible memory location.
PREP INSTA
prepinsta.com › home › all about c language › null pointer in c
Null Pointer In C
January 17, 2023 - A pointer is referred to as a null pointer if there is no address that can be allocated to it. The pointer is regarded as a Null pointer when a NULL value is assigned to it. ... #include<stdio.h> void main () { int val1, val2; int *ptr = 0; ...
W3Schools
w3schools.com › c › c_null.php
C NULL
C Examples C Real-Life Examples C Exercises C Quiz C Code Challenges C Practice Problems C Compiler C Syllabus C Study Plan C Interview Q&A ... NULL is a special value that represents a "null pointer" - a pointer that does not point to anything.
IncludeHelp
includehelp.com › c-programs › an-example-of-null-pointer-in-c.aspx
An Example of Null pointer in C
March 10, 2024 - The word "NULL" is a constant in C language and its value is 0. In case with the pointers - if any pointer does not contain a valid memory address or any pointer is uninitialized, known as "NULL pointer".
LabEx
labex.io › tutorials › c-using-null-pointer-in-c-programming-123293
Using Null Pointer in C Programming
A null pointer is a pointer that does not point to any memory address. In C programming, a null pointer is represented by the constant NULL, which is defined in the header file stdio.h.
Top answer 1 of 14
289
In my experience, tests of the form if (ptr) or if (!ptr) are preferred. They do not depend on the definition of the symbol NULL. They do not expose the opportunity for the accidental assignment. And they are clear and succinct.
Edit: As SoapBox points out in a comment, they are compatible with C++ classes such as unique_ptr, shared_ptr, auto_ptr that are objects that act as pointers and which provide a conversion to bool to enable exactly this idiom. For these objects, an explicit comparison to NULL would have to invoke a conversion to pointer which may have other semantic side effects or be more expensive than the simple existence check that the bool conversion implies.
I have a preference for code that says what it means without unneeded text. if (ptr != NULL) has the same meaning as if (ptr) but at the cost of redundant specificity. The next logical thing is to write if ((ptr != NULL) == TRUE) and that way lies madness. The C language is clear that a boolean tested by if, while or the like has a specific meaning of non-zero value is true and zero is false. Redundancy does not make it clearer.
2 of 14
65
if (foo) is clear enough. Use it.
Javatpoint
javatpoint.com › null-pointer-in-c
Null Pointer in C - javatpoint
Null Pointer in C with programming examples for beginners and professionals covering concepts, control statements, c array, c pointers, c structures, c union, c strings and more.
Codecademy
codecademy.com › docs › pointers › null pointer
C | Pointers | Null Pointer | Codecademy
February 3, 2025 - In the example, we declare an integer pointer ptr and initialize it to NULL, indicating that it doesn’t point to any valid memory location: ... The if statement checks if ptr is NULL, if true, it prints “Pointer is NULL” to the screen.
Uncodemy
uncodemy.com › blog › null-pointer-in-c-and-c-plus-plus-meaning-and-usage
Null Pointer in C and C++: Meaning and Usage
1 month ago - It doesn't mean there’s no envelope — it means the envelope is addressed to no one. If the postman (compiler) tries to deliver it, the system will get confused or crash. Just like you wouldn’t expect a letter with no address to reach anyone, you shouldn’t expect a null pointer to successfully access memory.