Why is it necessary to explicitly call `delete` in C even when the program is exiting?

Why Call Delete in C When the Program Exits?

In C , it is crucial to explicitly call the delete operator to deallocate heap-allocated memory, even when the program is exiting. While operating systems generally free memory upon program termination, this practice has several benefits:

Execution of Destructor Code:

• The destructor of an object is automatically called when its memory is deallocated.
• This allows you to perform essential cleanup tasks, such as closing files or writing data to a log file, before the memory is freed.
• If the OS frees the memory without calling the destructor, this cleanup code will not be executed.

Good Practice and Memory Leaks:

• It is good practice to explicitly delete heap allocations to avoid memory leaks.
• A memory leak occurs when allocated memory is not deallocated, potentially causing your program to run out of memory or experience performance problems.
• By calling delete, you ensure that the allocated memory is returned to the system.

Code Refactoring:

• Refactoring code may involve moving allocations to different locations within the application.
• If delete was not explicitly called in the original code, it may be forgotten in the new location, leading to memory leaks.
• Explicitly deleting allocations makes it clear where the memory is being deallocated, regardless of potential code changes.

Example:

Consider the following C main function:

int main(...)
{
    A* a = new A();
    a->DoSomething();
    delete a;
    return 0;
}

In this example, it is crucial to call delete a because:

• It ensures that the destructor of a is called, allowing any necessary cleanup tasks to be performed.
• It avoids a memory leak by returning the allocated memory to the system.
• It makes the code clearer and easier to maintain, as it explicitly specifies where the memory is deallocated.

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