Random get element from a jagged array

Questions & Answers
1

//Column
public GameObject plastic;
public GameObject paper;
int x;

    //Row
    public GameObject[] sort;
    int y;

    public GameObject[][] rubbish;
    int currentY, currentX;

    // Use this for initialization
    void Start()
    {
        plastic = GameObject.FindGameObjectsWithTag("Plastic");
        paper = GameObject.FindGameObjectsWithTag("Paper");
        sort = GameObject.FindGameObjectsWithTag("Sort");

        for (y = 0; y < sort.Length; y++)
        {
            rubbish = new GameObject[sort.Length][];

            for (x = 0; x < plastic.Length || x < paper.Length; x++)
            {
                rubbish[0] = plastic;
                rubbish[1] = paper;

                Debug.Log(y + " " + x + " " + rubbish[y][x].name);
                
                //paper.length=3
                currentX = Random.Range(0, paper.Length - 1);

                //sort.length=2
                currentY = Random.Range(0, sort.Length - 1);

                Debug.Log("Random rubbish:" + currentY + " " + currentX);
            }
        }

I have a jagged array with index first row: [0][0], [0][1], [0][2], second row: [1][0], [1][1], [1][2].
Here my code to get random element from the jagged array, and I face some problem:
The random element always I get is [0][0] and [0][1], while the other elements are never getting picked.
I can’t figure out why this happened.

2

because Range with integers excludes the last number already. putting Length suffices.

3

I confuse it with the float and int, and I just found it out.

Thank you for your help.