title: Can an undeclared pointer in C be auto-assigned to NULL by any chance?
body: <p>I want to check if a defined struct has been initialized
  So i thaught of using</p>
  
  <pre><code>typedef struct
  {
      int *isInitialized;
  } Thing;
  
  int main()
  {
      Thing a;
      //Only if initialized, should always fail now
      if (a.isInitialized == NULL)
      {
          //Code
      }
      //I'm saying a is initialized
      a.isInitialized = NULL;
  }
  </code></pre>
  
  <p>Will this work or is there any (even small) chance the pointer will automatically be assigned to NULL when declaring a?</p>
  
  <p>EDIT: 
  I know it is not always NULL.
  I'm asking if it is ever NULL or will it always be some random not-NULL pointer</p>