跨类实现和维护价值的最佳方式

Question

So, for fun while I'm in my early college I decided it would be good practice to program various projects. One project I'm working on is basically just a text based game. I'm implementing spells and abilities, and I have a string array for my enemies, I'd like to maintain the random value(enemy) that is generated from this code to my abilities class for calculation. Should I even go with another class for abilities and spells? I'm not entirely sure I'm on the right track to developing proper OOP programming practices and habits, so if anyone can help to point me to the right path, I'd appreciate it.

System.out.println("Welcome to Mysterical World of Mysterical Things!");
System.out.println("Please press the number corresponding the action you wish to take.");   
//Clause to keep the game running with invalid inputs
GAME:


while(running) {
    System.out.println("-----------------------------------------------");
    int enemyHealth = rand.nextInt(maxEnemyHealth);
    String enemy = enemies[rand.nextInt(enemies.length)];
    System.out.println("\t### " + enemy + " has appeared! ###\n");

And the class I'm trying to maintain that string enemy value is:

public void fireBlast(int fb) {

    fb = 5;

    System.out.println("You cast Fire Blast!");
    int damageTaken = rand.nextInt(enemyAttackDmg);
    enemyHealth -= fb*level;
    health -= damageTaken;
    System.out.println("\t>>> You hit the " + enemy + " for " + fb + " damage <<<");
    System.out.println("\t>>> You took " + damageTaken + " <<<");

Answer 1

As a rule of thumb, globals = bad. Evil Globals

Of course, if you stuck with methods instead of classes, you could just have class variables declared outside main().

You do have some options though. You could pass in the String or String[] as an argument in the functions that you want to have access to them. So if you have some String[] of enemies, and you want to pass them into a funciton of another class...

MiddleEarth me = new MiddleEarth(); // MiddleEarth is a class, me is the instance of that class
me.mordor(enemies); // I have now passed the enemies into the function Mordor of the class MiddleEarth

And now, in the middle earth class, you need mordor() to accept a String or String[] of enemies:

public class MiddleEarth {
  public MiddleEarth() {
    //constructor
  }

  public void mordor(String[] enemies) {
    // do something with enemies
  }
}

The other, less advisable option is to have an interface named Globals and store variables you want accessible from all classes in there, and implement that interface in the classes you want to have access to these global vars. I don't recommend this at all.

Also - why do you pass in int fb to fireBlast() if the first thin you do is set it to 5? This defeats the purpose.