NullReferenceException: Object reference not set to an instance of an object CreationSphère.Update

Hello everyone ! First, I'm French so sorry for my english.
I started to use Unity last week so i'm a debutant.

I'm trying to do a Tic-Tac-Toe in 3D. I have a code in C# to the console and I want to use the same to Unity.
Here, I try to print my array.

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class CreationSphère : MonoBehaviour
5. {
6.  
7.     public GameObject Boule;
8.     public GameObject Cube;
9.  
10.  
11.     void Start()
12.     {
13.  
14.     }
15.  
16.    
17.     void Update()
18.     {
19.         if (Input.GetKey(KeyCode.Space))
20.         {
21.             int[][] matrix = new int[3][];
22.             matrix[0][1] = 1;
23.             matrix[1][2] = 2;
24.             print_matrix(matrix, Boule, Cube); //My test.
25.         }
26.  
27.     }
28.  
29.  
30.     void print_matrix(int[][] array, GameObject rond, GameObject croix) //Croix = player 2
31.     {
32.  
33.         int scare = array.Length;
34.         for (int i = 0; i < scare; i++)
35.         {
36.             int a = 5;
37.             for (int j = 0; j < scare; j++)
38.             {
39.                 int b = 5;
40.                 Vector3 position = new Vector3(a, 0, b);
41.                 switch (array[i][j])
42.                 {
43.                     case 1:
44.                         Instantiate(rond, position, Quaternion.identity);
45.                         break;
46.  
47.                     case 2:
48.                         Instantiate(croix, position, Quaternion.identity);
49.                         break;
50.  
51.                     case 0:
52.                         break;
53.                 }
54.                 b += 10;
55.  
56.             }
57.             a += 10;
58.         }
59.     }
60.  
61. }

And the error is enclosed.

Thanks for your help and sorry for my english.

 

Hi , try to change the array codes like this:

Code (CSharp):

1. int[,] matrix = new int[3,3];
2.             matrix[0,1] = 1;
3.             matrix[1,2] = 2;

The rest will need changing as well.

 

Yeah my bad, I wrote my test like a two-dimensionnal array and not a jagged array.
Here there is my correction for a jagged array:

Code (CSharp):

1. void Update()
2.     {
3.         if (Input.GetKey(KeyCode.Space))
4.         {
5.             int[][] array = init_matrix(3);
6.             array[1][0] = 1;
7.             array[0][2] = 2;
8.             print_matrix(array, Boule, Cube);
9.         }        
10.  
11.     }
12.  
13.  
14.     static int[][] init_matrix(int n)
15.     {
16.         int[][] matrix = new int[n][];
17.         for (int x = 0; x < matrix.Length; x++)
18.         {
19.             matrix[x] = new int[n];
20.         }
21.         return matrix;
22.     }

Thanks for your help.
Do you know if there is a débogueur for Unity ?