• 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...
    17 KB (2,095 words) - 05:44, 2 July 2025
  • Thumbnail for Pointer (computer programming)
    pointer be explicitly initialized to the null pointer value, which is traditionally specified in C with the standardized macro NULL: int *ptr = NULL;...
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  • often occur because of errors in pointer use, particularly in C dynamic memory allocation. Dereferencing a null pointer, which results in undefined behavior...
    19 KB (2,431 words) - 08:02, 13 April 2025
  • 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,...
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  • Thumbnail for C (programming language)
    with the null-terminated string convention and the standard library provides handling Supports low-level access to computer memory via pointers Supports...
    98 KB (10,783 words) - 01:38, 12 July 2025
  • following limits on programs: NULL checks are inserted to prevent segmentation faults Pointer arithmetic is limited Pointers must be initialized before use...
    11 KB (1,181 words) - 03:20, 13 April 2025
  • Thumbnail for Dangling pointer
    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...
    15 KB (1,891 words) - 06:59, 11 June 2025
  • 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...
    102 KB (13,190 words) - 17:45, 23 June 2025
  • 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...
    6 KB (616 words) - 19:12, 12 September 2024
  • no appropriate object available. A null reference is impossible in standard-conforming C++. A null Animal* pointer is possible, and could be useful as...
    22 KB (2,802 words) - 21:39, 9 March 2025
  • 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...
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  • 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...
    8 KB (704 words) - 01:51, 31 January 2025
  • bugs; Swift has features addressing some common programming errors like null pointer dereferencing and provides syntactic sugar to help avoid the pyramid...
    79 KB (7,948 words) - 06:31, 13 June 2025
  • 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...
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  • Thumbnail for Rust syntax
    Though null pointers are idiomatically avoided, the null pointer constant in Rust is represented by std::ptr::null(). Rust also supports raw pointer types...
    49 KB (4,638 words) - 22:16, 8 July 2025
  • Thumbnail for C syntax
    C syntax (section Pointers)
    programmers [who?] then set the pointer variable to NULL: free(a); a = NULL; This ensures that further attempts to dereference the pointer, on most systems, will...
    84 KB (10,762 words) - 03:41, 11 July 2025
  • 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...
    18 KB (1,911 words) - 12:35, 18 June 2025
  • 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...
    22 KB (2,809 words) - 12:49, 5 July 2025
  • 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...
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  • (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...
    55 KB (7,796 words) - 18:31, 7 July 2025
  • 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...
    3 KB (411 words) - 07:37, 1 September 2024
  • Thumbnail for Zig (programming language)
    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...
    34 KB (3,441 words) - 14:50, 27 June 2025
  • 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...
    49 KB (4,685 words) - 18:32, 11 July 2025
  • 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...
    36 KB (4,141 words) - 04:19, 26 June 2025
  • pointers, A null pointer type with only one value, null, indicating an exceptional condition. Unfortunately, C compilers do not verify that the null case...
    26 KB (3,515 words) - 17:39, 13 March 2025
  • 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...
    9 KB (1,123 words) - 16:12, 25 September 2024
  • result of applying the unary * operator on a null pointer. Whether an exception is thrown for other null reference arguments is implementation-dependent...
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  • object-oriented programming languages when one of the objects may be a null pointer. Most modern object-oriented programming languages use a coding style...
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  • Thumbnail for Srm (Unix)
    null_pointer at SourceForge (9 June 2011). "srm main.c" (C Source). srm 1.2.11, main.c CVS 1.16. SourceForge.net. Retrieved 7 January 2014. doj, null_pointer...
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  • expression for rejecting all available candidates None, the keyword for the null pointer in Python Nones (disambiguation) Nothing (disambiguation) Zero (disambiguation)...
    981 bytes (157 words) - 21:20, 1 March 2025