Iterating through children of transform: is there an order guarantee?

Questions & Answers
1

If I iterate through the children of a transform with a foreach loop, is there any guarantee for the order in which the children are enumerated?

E.g. if I set up a test scene with the following hierarchy:

1439-testHierarchyScreenshot.png

And then I use a foreach loop to iterate through the children of “Cube”:

	foreach(Transform child in this.transform)
		Debug.Log(child.name);

What happens is that A B C D is always printed in alphabetical order. Is this a guarantee though? An alphabetical-order traversal isn’t defined in the documentation for Transform.

The reason why I ask is because I am iterating over multiple transform hierarchies that have an identical structure, and it would be nice to know if there is some sort of order guarantee when iterating through children.

2

I don’t think there is a guarantee and if there is an order it would more likely to be the order that you added them.

You could guarantee your own order like this:

  using System.Linq;
  using System.Collections.Generic;

  ...

  foreach(var child in transform.Cast<Transform>().OrderBy(t=>t.name))
  {
  }
3

You can set the order by order you added them thus

foreach (var child in parentTransform.Cast<Transform>().OrderBy(t => t.GetSiblingIndex()))