Resizing Memory

Resizing Memory

• Resizing memory in C is typically done using the realloc function, which is used to change the size of an already allocated memory block.

Things to be considered using realloc:

• It's important to note that realloc may move the memory block to a different location if necessary.

• If this happens, any pointers to the original memory block become invalid, so we need to make sure to update any pointers to the new memory location.

-It's also important to properly manage dynamically allocated memory to avoid memory leaks. Always make sure to deallocate memory using the free function when it's no longer needed.

Example

#include <stdio.h>
#include <stdlib.h>

int main() {
    // Allocate memory for an array of 5 integers
    int* dynamicArray = malloc(5 * sizeof(int));

    if (dynamicArray == NULL) {
        printf("Failed to allocate memory.\n");
        return 1; // Error handling
    }

    // Use the dynamically allocated memory

    // Resize the array to 10 integers
    dynamicArray = realloc(dynamicArray, 10 * sizeof(int));

    if (dynamicArray == NULL) {
        printf("Failed to reallocate memory.\n");
        return 1; // Error handling
    }

    // Use the resized memory block

    // Deallocate the memory when done
    free(dynamicArray);

    return 0;
}

Explanation:

• Here, we first allocate memory for an array of 5 integers using the malloc function.
• Then, we use the realloc function to resize the memory block to an array of 10 integers.
• If the reallocation is successful, the pointer returned by realloc points to the beginning of the new memory block.
• If it fails, it returns NULL, in which case we need to handle the error.