Dangling Pointer in C

Dangling Pointer :

A dangling pointer in C is a sort of initialized pointer that exists because the programmer failed to initialize it with a proper address.

Dangling Pointer in C

About Dangling Pointer :

  • Dangling Pointers, as the name implies, are pointers that point to memory locations that have been released or removed by the application.
  • Dynamic Memory Allocation principles are used while discussing the allocation and deallocation of memory blocks.
  • In Dynamic Memory Allocation, we typically employ the C methods malloc(), calloc(), and free() to allocate and deallocate memory blocks.
  • Consequently, a Dangling Pointer is created after we deallocate a memory block using the free() method.

Examples of Dangling Pointer  :

Let,s see some example for better understanding the dangling pointer in C

Example 1

int *help(){  
    int val = 20;  
    return &val;  
int main() {  
    int *ptr = help();  
    printf("%d", *ptr);  
    return 0;  

Output :
Segmentation fault

Avoiding Dangling Pointer :

  • Initializing the pointer to the NULL value will prevent dangling pointer errors.
  • The pointer will not point to the de-allocated memory if the NULL value is assigned to it.
  • When a pointer is given the value NULL, it indicates that it is not pointing at any memory address.

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