Hello

[MaseratiDeluxe]

I was wondering if i can get some help answering these questions or pointed in the right direction.

1. How does a function pass control back to the calling function?

2. How do you declare a local variable to be static?

3. Show how to dynamically allocate an array of doubles of size N?

im having trouble finding them in my book.

thank you.

[N36fSL3A]

1. How does a function pass control back to the calling function?

Not sure what you mean. Once the function goes out of scope, the calling function resumes.

2. How do you declare a local variable to be static?

void func()
{
    static int x = 0;
}

3. Show how to dynamically allocate an array of doubles of size N?

int* arr = new int[N * 2];

[wildblue]

Array of doubles of size N? (If you didn't mean twice the size of N)

3. Show how to dynamically allocate an array of doubles of size N?

double * arr = new double[N];

[N36fSL3A]

Yea, I read the last one wrong, wildblue is correct.

[TwilightSpectre]

For 1), when a function is called the location from where it is called is pushed onto the call stack, and upon a return the function is popped from the stack and control returns to the last point of execution, where the caller can retrieve the return value from a register.

In assembly, this can be done through the instruction call func_name, which then jumps to func_name. Then the ret function is called, which pops the stack and returns to the call. Here is an example in NASM syntax assembly:

  call func_name    ; push the return address on the stack
  ...

func_name:
  xor eax, eax
  ret               ; pushes the return value into [esp]