How to check if a c# 3d array index exists?

Questions & Answers
1

How do I check if a multi-dimentional array index reference is beyond the range of the array?

GameObject[, ,] objectMatrix = null;

void Start () {
 objectMatrix = new GameObject[9,33,33]; //range is less than 100
}

void Update () {
 if(objectMatrix[100,100,100] == ???){ //Code stops here. This index does not exist.
  print("This index is beyond the array's range.");
 }
 print (objectMatrix[100,100,100]); //Code stops anytime the index is out of range.
}

The above paraphrased code fails to do anything. It just stops at the illegal index in either the print function or if statement; no errors or warnings. What can I replace the ‘???’ with to check if the index is legal?

I’m using this array to store the 3d grid locations of cubes, to check that no cube is generated at an occupied address, and eventually to save/load the arrangement.

2

You can use GetLength() with the index of the dimension to check an index against the size before accessing:

GameObject[, ,] objectMatrix = null;
 
void Start () {
    objectMatrix = new GameObject[11,22,33]; //range is less than 100
    Debug.Log(objectMatrix.GetLength(0)+","+objectMatrix.GetLength(1)+","+objectMatrix.GetLength(2));
}

The Debug.Log() output, “11,22,33.”