Dynamic Array Allocation in C with Variable Array Size

Variable-sized arrays, also known as dynamic arrays, pose a challenge in standard C. Consider the following program:

n = fread(Sbuf, sizeof(char), siz, picture);
/* ... do stuff with the buffer ... */
/* memset(Sbuf, 0, sizeof(Sbuf)); */

}

The code above attempts to allocate an array of characters with a size determined by a variable siz. However, in standard C, array sizes must be constants. This poses the question: how can we declare siz correctly to allow code compilation?

Unfortunately, there is no direct method to declare an array with a variable size in standard C. However, several alternatives exist:

• std::vector: In modern C , the std::vector container can be used as a flexible alternative to arrays. It can be easily extended to any desired size and its usage is relatively straightforward.
• New operator: The new operator can be employed to allocate memory dynamically on the heap. To create an array with a variable size, one can use char* Sbuf = new char[siz]; to allocate an array of siz characters on the heap. However, this approach introduces memory management concerns (e.g., potential memory leaks), making it less suitable than std::vector.