Time for action – to catch a competitor

Combine these two separate function calls:

 square = Win();
  if(square == null) square = Block();
  if(square == null) square = CreateTrap();
  if(square == null) square = PreventTrap();

into this unified call:

 square = Win();
  if(square == null) square = Block();
  if(square == null) square = PreventOrCreateTrap();

The PreventOrCreateTrap function is very straightforward:

function PreventOrCreateTrap():GameObject
{
  var aP1Corners:List.<GameObject> = new List.<GameObject>(); 
    // Create an empty list to store X-controlled corners
  var aP2Corners:List.<GameObject> = new List.<GameObject>(); 
    // Create an empty list to store O-controlled corners
  var aOpenCorners:List.<GameObject> = new List.<GameObject>(); 
    // Create an empty list to store unoccupied corners
  
  var aCorners:GameObject[] = [aGrid[0,0],aGrid[2,0],aGrid[0,2],
    aGrid[2,2]]; 
    // Create an array to store the corner coordinates
...