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scope question nested loops

technologist (607)
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(expression 1)
         {statement 1}
                    .
                    .initialize vars for next loop
                    .
                (expression 2)
                           {statement 2}


If I am initializing vars in first statement for second loop what is my scope? Both loops or the nested loop. In this example the game is restarted/reinitialized
with the first loop so that var initialization in first loop is probably appropriate.
Last edited on
Duthomhas (13212)
A { introduces a new scope. Variables introduced in that scope are invisible to the enclosing scope. So a good rule of thumb is to declare variables in the smallest scope in which they are used.

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  {
    int n = 12;
    cout << "n = " << n << "\n";
    {
      int x = 3;
      n += x;
      cout << "x = " << x << "\n";
    }
    // x no longer exists
    cout << "n = " << n << "\n";
  }
  // n no longer exists

Hope this helps.
technologist (607)
Thx Duoas

{older scope
{new scope
...int x = 3;
}
{
x can be seen within new scope but not from older scope
is that correct?

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{
    int n = 12;
    cout << "n = " << n << "\n";
    {
      int x = 3;
      n += x;
      cout << "x = " << x << "\n";
    }
    // x no longer exists
    cout << "n = " << n << "\n";
  }
  // n no longer exists


That is helpful. Checking to see if my understanding is ok.
Last edited on
Duthomhas (13212)
Correct. After 'this closing' the x variable no longer exists.
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