Comparing a String to a String in an Array

[Brandon Golway]

I converted a game that I wrote in Python to java (since Im currently learning it in my college class) and I cant figure out how to compare a string to a string in an array without doing a lot of coding. All I basically want is if the player finds a weapon it gets added to their weapon array, then when you call the inventory function it will list the players weapons.

Heres the simpliest excerpt I could make

String found_weapon = "knife";

public static void AddWeapon (String found_weapon)
	{
		
		your_weapons = new String [3]; //size is 3 since there are only three weapons
		
		if (found_weapon.contentEquals("knife"))
			your_weapons[0] = "knife";
				
		if (found_weapon.contentEquals("pistol"))
			your_weapons[1] = "pistol";
		
		
		if (found_weapon.contentEquals("rifle"))
			your_weapons[2] = "rifle";
		
	}
	
	public static void ListWeapons ()
	{
		if (your_weapons[0].contentEquals("knife"))
			System.out.print("knife");
		
		if (your_weapons[1].contentEquals("pistol"))
			System.out.print(",pistol");
		
		if (your_weapons[2].contentEquals("rifle"))
			System.out.print(",rifle");
				
	}

the first line of ListWeapons() throws a NullPointerException

[Kevin Workman]

Stupid question- Do you actually ever call AddWeapon (which should be addWeapon, by the way) with each parameter?

Posting an SSCCE would help clear up any more confusion about what you're doing, which would help you get assistance faster.

[Mike Peters]

You may consider using a set:

import java.util.HashSet;
import java.util.Set;

public class WeaponInventory {
    private final Set<String> weapons = new HashSet<String>();

    public void add(String weapon) {
        weapons.add(weapon);
    }

    public void list() {
        StringBuilder sb = new StringBuilder();
        for (String weapon : weapons) {
            if (sb.length() != 0) {
                sb.append(',');
            }
            sb.append(weapon);
        }
        System.out.print(sb);
    }
}

[Brandon Golway]

That worked, thanks Mike!

[Wouter Oet]

Kevin Workman wrote:Stupid question

There are no stupid questions only stupid answers. Remember that we'll had to learn Java at one point.

[Mike Peters]

My pleasure Brandon. Good luck and don't hesitate to ask questions!

[Kevin Workman]

Wouter Oet wrote:

Kevin Workman wrote:Stupid question

There are no stupid questions only stupid answers. Remember that we'll had to learn Java at one point.

I was saying my question was stupid, not the OP's. It's easy to miss the "obvious" stuff when you've been staring at the same code for days, so sometimes all it takes is somebody else asking a stupid question to help you along.

[Wouter Oet]

Aha then I misinterpreted it. But my post still stands.