Transform.childCount

Description

The number of children the parent Transform has.

Note: The parent is not included in the count.
Note: Inactive GameObjects get included in the count.

using UnityEngine;

public class ExampleClass : MonoBehaviour
{
    // generate a group of connected GameObjects
    void Awake()
    {
        GameObject go = new GameObject("top");

        Random.InitState(System.Environment.TickCount);

        // add 3, 4 or 5 "middle" children that report to "top"
        for (int i = 0; i < Random.Range(3, 6); i++)
        {
            GameObject go2 = new GameObject("middle" + i.ToString());
            go2.transform.parent = go.transform;

            // add between 1 to 8 "bottom" children that report to the above "middle"
            for (int j = 0; j < Random.Range(1, 8); j++)
            {
                GameObject go3 = new GameObject("bottom" + j);
                go3.transform.parent = go2.transform;
            }
        }
    }

    void Start()
    {
        // how many children does top have?
        GameObject go = GameObject.Find("top");
        Debug.Log(go.name + " has " + go.transform.childCount + " children");

        // pick a random middle group and pick a member of its children
        go = GameObject.Find("middle" + Random.Range(0, go.transform.childCount));
        Debug.Log(go.name + " has " + go.transform.childCount + " children");
    }
}