非常大的特定2d数组for循环在随机点中返回空值

Question

I have a huge double for loop to fill a 2d array, based on a very specific set of criteria. I'm displaying this 2d array in a JOptionPane; on some runs of the program, I get no "null", on others, I get lots of them. There doesn't appear to be a pattern of where/when it occurs.

This leads me to believe my issue has to deal with my "else if" criteria.

My array is filled with different strings depending on: If there are Monsters in the cell, if there is a piece of Armour, if there is a Weapon, if there is Nothing, or if there is a combination of any assortment of the above (monster + weapon, monster + armour, etc).

This has lead me to make the following chain of if/else if:

if(map[a][b] == map[0][0])      //sets the first cell as the entrance
...
else if(!x.hasAM()  && armour == 0 && weapons == 0)         //has nothing
...
else if(!x.hasAM() && armour > 0 && weapons == 0)           //has armour
...
else if(!x.hasAM() && armour == 0 && weapons > 0)           //has weapon
...
else if(x.hasAM() && armour == 0 && weapons == 0)           //has monster
...
else if(x.hasAM() && armour > 0 && weapons == 0)        //has monster, has armour
...
else if(x.hasAM() && armour == 0 && weapons > 0)        //has monster, has weapon
...
else if(x.hasAM() && armour > 0 && weapons > 0)     //has monster, has armour, has weapon

In some of these, the way I assign the string is simply "map[a][b] = "|________|";". In others I have nested Switches. I don't think that's the issue, though, because the strings that are generated by the nested Switches work. But obviously I have no clue what the issue is, so just in case here is an example of the most "complex" set up:

else if (Player.type.equalsIgnoreCase("Ranger")) {
    if (Cell.monsters.length == 4) {
        switch (weapons) {
            case 1:
                switch (armour) {
                    case 1:
                        map[a][b] = "|_!Sl@L__XXXX|";
                        break;

                    case 2:
                        map[a][b] = "|_!Sl@C__XXXX|";
                        break;

                    case 3:
                        map[a][b] = "|_!Sl@P__XXXX|";
                        break;

                    case 4:
                        map[a][b] = "|_!Sl@M__XXXX|";
                        break;
                }
                break;
        }
    }
}

The issue I'm having is that sometimes the output of my program is like this:

|_!Sl@M__XXXX| |_!Sl@M__XXXX| null null |_!Sl@M__XXXX|
null |_!Sl@M__XXXX| |_!Sl@M__XXXX| null null

etc.

Here is the full method, in case I'm wrong about it being my "else if" statements and you want to look at the whole thing: https://gist.github.com/anonymous/7518098

And as always, thanks in advance! :D

Answer 1

Okay. You're clearly missing some combination of armor, player type, weapons, and number-of-monsters in your long if - else if chain. We could try to analyze it in detail, but the structure of your code makes that really difficult to do. (the comments about restructuring your code are on point, even if you don't really know how to do that yet)

Therefore, let's ask the program to tell us what combination is being missed.

I would recommend that you add this in line 1275, right before the "builder.append" line:

if (map[a][b] == null) {
    System.out.println("Missed case! Player.type is " + Player.type
                       + " and weapons is " + weapons
                       + " and armour is " + armour
                       + " and Cell.monsters.length is " + Cell.monsters.length);
}

Then, run your program and find out which combination is being missed and trace it down. Then keep coding and working on your code structure because it can get better, but generally requires practice.