int somehow losing it's value?

Unity Engine
1

HI,

Trying to write a program to randomly generate a path across a grid, but for some reason the int playerCol resets it’s value back to 0 for some unknown reason.

Both playerCol and startCol are intiated at 0. Then startCol is randomized between 0 - 9 (10 columns) at line 50. At line 52 playerCol is given the same value as startCol, let us just 8 for example.

Then is goes through a series of 4 methods to determine if the next square in that direction is available. Problem is West keep coming up false, even with it should be true. Through a series of Debug statements I find that playerCol holds it’s value (8) after North(), after South() and after East(), line 61 print 8, but the next line calls the West() method and the first line in West(), playeCol reads 0. startCol holds it’s value(8), but not playerCol.

This has been confirmed by default.log and values as shown in the inspector.

Any ideas?

Thanks.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class GameController : MonoBehaviour
{
    public int[,] mazeArray;
    public int startRow = 0;
    public int startCol = 0;
    public int playerRow = 0;
    public int playerCol = 0;

    private bool nortest = false;
    private bool soutest = false;
    private bool westest = false;
    private bool eastest = false;

    private int mapCode = 0;

    private List<string> dirction = new List<string>();
    
    void Start ()
    {
        mazeArray = new int[8, 10]; // rows, columns
        dirction.Clear();           // clear list
        ResetArray();               // set all elements to 0
        GeneratePath();             // generate random path

    }
   
    void Update ()
    {
       
    }

    void ResetArray()
    {
        for (int i = 0; i < 8; i++)
        {
            for (int j = 0; j < 10; j++)
            {
                mazeArray[i, j] = 0;
            }
        }
        return;
    }

    void GeneratePath()
    {
        startCol = Random.Range(0, 10);
        mazeArray[startRow, startCol] = mapCode = 1;
        int playerCol = startCol;
        int test = 0;  // used to limit while loop
        while ( test < 1 )                  //(tempRow < 7)
        {
            North();
            Debug.Log(playerCol.ToString());
            South();
            Debug.Log(playerCol.ToString());
            East();
            Debug.Log(playerCol.ToString());
            West();

            //SelectDir();

            test++;
        }
        //Debug.Log("start row " + startRow.ToString());
        //Debug.Log("start col " + startCol.ToString());
        //Debug.Log("north = " + nortest);
        //Debug.Log("south = " + soutest);
        //Debug.Log("east = " + eastest);
        //Debug.Log("west = " + westest);
        //Debug.Log(playerRow.ToString());
        //Debug.Log(playerCol.ToString());
                      
    }

    void North()
    {
        if (playerRow + 1 == 7)
        {
            nortest = false;
            return; // make finish block
        }
        else if (mazeArray[playerRow + 1, playerCol] != 0)
        {
            nortest = false;
            return;
        }
        else dirction.Add("north");
        nortest = true;
        return;
    }

    void South()
    {
        if (playerRow - 1 < 0)
        {
            soutest = false;
            return;
        }
        else if (mazeArray[playerRow - 1, playerCol] != 0)
        {
            soutest = false;
            return;
        }
        else dirction.Add("south");
        soutest = true;
        return;
    }

    void East()
    {
        if (playerCol + 1 > 9)
        {
            eastest = false;
            return;
        }
        else if (mazeArray[playerRow, playerCol + 1] != 0)
        {
            eastest = false;
            return;
        }
        else dirction.Add("east");
        eastest = true;
        return;
    }

    void West()
    {
        Debug.Log(playerCol.ToString());
        Debug.Log(startCol.ToString());
        if (playerCol - 1 < 0)
        {
            westest = false;
            Debug.Log("if one");
            Debug.Log(playerCol.ToString());
            return;
        }
        else if (mazeArray[playerRow, playerCol - 1] != 0)
        {
            westest = false;
            return;
        }
        else dirction.Add("west");
        westest = true;
        return;
    }

    void SelectDir()
    {
        int select = 0;
        string selection = "";
        if (dirction.Count != 0)
        {
            select = Random.Range(0, dirction.Count + 1);
            Debug.Log("direction count = " + dirction.Count);
            Debug.Log("selection = " + selection.ToString());
            selection = dirction[select];
            Debug.Log(selection);
        }
        else selection = "blocked";

        switch (selection)
        {
            case "blocked":
                break; // TODO - add back up method
            case "north":
                playerRow = playerRow + 1;
                break;
            case "south":
                playerRow = playerRow - 1;
                break;
            case "east":
                playerCol = playerCol + 1;
                break;
            case "west":
                playerCol = playerCol - 1;
                break;
            default:
                break;          
        }


        return;
    }
}
2 
// line 52 : change this
        int playerCol = startCol;
// to this
        playerCol = startCol;

Problem is the scope of your variables. You are declaring and assigning (at line 52 in your post) a new local variable.
Simply assign it, but do you declare it , ie: remove ‘int’ on that line.

1 Like
3

Stupid! Stupid! Stupid! :rage: I feel like a complete idiot now.

I was about to ask another stupid question but I just answered it myself. I was going to ask why North(), South() and East() worked, but I never actually debugged inside of those methods , just after them, and none of them were dependent on playerCol being 0.

I even know how it happened now. I originally was using an extra set of variables called tempCol and tempRow, which I was using local. When I realized the variables were going to have to be passed between methods I decided to just use the two fields I already had, playerCol & playerRow and I could just reset them after the map was generated. I removed the int from playerRow, but totally missed the int in front of playerCol.

Stupid! Stupid! Stupid!

Thanks so much methos5k.

4

Ah, it’s just a little mistake. No worries. They happen :slight_smile: Glad it’s working now. Cheers.