Lab 8: Experiment 9

Using a Twice-Declared Identifier in Inner Block

Issue: Suppose an identifier has two different declarations, one in an outer block and one in a nested inner block. If the name is accessed within the inner block, which declaration is used?

Hypothesis: The closest definition will be used.

Proximity sounds like a good rule of thumb — whatever was done most recently matters the most.

The Experiment: When we display the value of arg1 within the inner block, following its second declaration, we can get an answer to our question:

int main()
{
  int arg1;
  arg1 = -1;
  ...
  {
    char arg1 = 'A';
    cout << arg1 << endl;
  }
}

Question #8.9.1: If -1 is printed, what does this mean?

Question #8.9.2: If A is printed, what does this mean?

Observation: Compile and execute your program.

Question #8.9.3: What does the program display?

Conclusions:

Question #8.9.4: Is our hypothesis correct? How do you know? If it's not correct, what should it be?