A variable that is read-only after assignment at run-time?

Question

Fairly new programmer here, and an advance apology for silly questions.

I have an int variable in a program that I use to determine what the lengths of my a

Answer 1

I'd use a function-static variable and a simple function. Observe:

int GetConstValue(int initialValue = 0)
{
  static int theValue = initialValue;
  return theValue;
}

Since this is a function-level static variable, it is initialized only the first time through. So the initialValue parameter is useless after the first run of the function. Therefore, all you need to do is ensure that the first call of the function is the one that initializes it.