In computing, a null pointer (sometimes shortened to nullptr or null) or null reference is a value saved for indicating that the pointer or reference does...

garbage collection. A null pointer has a value reserved for indicating that the pointer does not refer to a valid object. Null pointers are routinely used...

often occur because of errors in pointer use, particularly in C dynamic memory allocation. Dereferencing a null pointer, which results in undefined behavior...

representation. Null device, a virtual file that discards data written to it, on Unix systems /dev/null Null pointer or reference (sometimes written NULL, nil,...

following limits on programs: NULL checks are inserted to prevent segmentation faults Pointer arithmetic is limited Pointers must be initialized before use...

syntax for null-terminated strings with associated handling in its standard library Supports low-level access to computer memory via pointers Supports procedure-like...

null pointer to his design of the ALGOL W language and called it a "mistake": I call it my billion-dollar mistake. It was the invention of the null reference...

never again be used, no code will try to access the null pointer, and because the pointer is null, its memory is not deleted when it goes out of scope...

system is able to detect run-time references to null pointers, a solution to the above is to assign 0 (null) to dp immediately before the inner block is...

no appropriate object available. A null reference is impossible in standard-conforming C++. A null Animal* pointer is possible, and could be useful as...

software documentation, the null character is often represented with the text NUL (or NULL although that may mean the null pointer). In Unicode, there is a...

unusable. This means that, for example, a pointer to 0 is never a valid pointer and can be used as a special null pointer value. Unlike the previously mentioned...

pointers that can be NULL require the user to check the pointer before using it and require specific code to handle the case when the object pointer is...

bugs; Swift has features addressing some common programming errors like null pointer dereferencing and provides syntactic sugar to help avoid the pyramid...

just the singular zero-valued null pointer, the Operating System can trap on code that, for example, has a null pointer pointing to a structure, and accesses...

(head == NULL) { head = temp; // If the linked list is empty (i.e., the head node pointer is a null pointer), then have the head node pointer point to...

pointers, A null pointer type with only one value, null, indicating an exceptional condition. Unfortunately, C compilers do not verify that the null case...

instance, creating a pointer with a null value and then attempting to use it is perfectly acceptable in C, leading to null-pointer errors. In contrast...

from the creation of such a reference. In Rust, dereferencing a null pointer (std::ptr::null()) in an unsafe block results in undefined behaviour, which usually...

result of applying the unary * operator on a null pointer. Whether an exception is thrown for other null reference arguments is implementation-dependent...

expression for rejecting all available candidates None, the keyword for the null pointer in Python Nones (disambiguation) Nothing (disambiguation) Zero (disambiguation)...

destructor of an RAII object may lead to unexpected results, Null pointer dereference – A null pointer dereference will often cause an exception or program termination...

might return a null pointer and it is good programming practice to check for this: int *array = malloc(10 * sizeof(int)); if (array == NULL) { fprintf(stderr...

Though null pointers are idiomatically avoided, the null pointer constant in Rust is represented by std::ptr::null(). Rust also supports raw pointer types...

ptr = NULL; // OK: modifies the pointer *ptrToConst = 0; // Error! Cannot modify the pointed to data ptrToConst = NULL; // OK: modifies the pointer *constPtr...

object-oriented programming languages when one of the objects may be a null pointer. Most modern object-oriented programming languages use a coding style...

singly linked list. The first one uses the sentinel value NULL, and the second one a (pointer to the) sentinel node Sentinel, as the end-of-list indicator...

C and C++, 0 represents the null pointer. As with Boolean values, the C standard library includes a macro definition NULL whose use is encouraged. Other...

offsetof(st, m) \ ((size_t)&(((st *)0)->m)) This can be understood as taking a null pointer of type structure st, and then obtaining the address of member m within...

can automatically detect such an invalid access (e.g. for the null value: a null pointer dereference error). This supports in analyzing the actual reason...