Real world pre/post-order tree traversal examples

Question

I understand pre-order, in-order, and post-order tree traversal algorithms just fine. (Reference). I understand a few uses: in-order for traversing binary search trees in order

Answer 1

As Henk Holterman pointed out, destroying a tree using manual memory management usually is a post-order traversal.

Pseudocode:

destroy(node) {
  if (node == null) return;

  destroy(node.left)
  destroy(node.right)

  // Post-order freeing of current node
  free(node)
}