HashMap

Can someone give me a link thats explains whats its HashMap?

 

ProStriker123
http://lmgtfy.com/?q=Java+HashMaps

 

Basically it is an ArrayList that stores two types of objects.
For instance, say that I wanted to make a killstreak plugin.
I would make a Hashmap that has a String and an Integer like so.

Code:

HashMap<String, Integer> killStreak = new HashMap<String, Integer>();

Now I can store a PlayerName and their KillStreak by doing...

Code:

int killStreakNumber = 3;
killStreak.put(p.getName(), killStreakNumber);

There are a variety of things you can store in a HashMap. Here are a couple of examples...

Code:

HashMap<String, String> kitName = new HashMap<String, String>();
kitName.put(p.getName(), "PVPKit");
 
HashMap<String, List<String>> teamList = new HashMap<String, List<String>>();
etc.

Here is another example of what you could do.

Code:

HashMap<String, String> kitName = new HashMap<String, String>();
//[HashMap].keySet();
 
for(String s : kitName.keySet()){
  System.out.println(s + " is the " + kitName.get(s) + " kit.");
}

This example shows that .keySet() will return the first object (in a List) in the HashMap which in that case, we used to store the PlayerName. I've created a loop for the list.
Doing kitName.get(s) [Their Name] will return their kitName which is our second object.

If you have any questions, I'd love to answer them.

 

stormneo7
Good explanation. However use the player's UUID instead of the player's name

 

xmarinusx just as an informational sidenote: you can use player names if they are only kept within the scope of login and quit, and not for persistence.

 

In which case you might as well use a Player object

 

@stormneo7,
@xmarinusx,
@fireblast709,
@Double0negative,
Thanks guy's its helped me very much.

 

As long as you handle the data correctly to avoid possible memory leaks.

 

fireblast709 Bukkit will soon put player objects in a hashmap, instead of a List, with the UUID as the key. So it will be more efficient storing the UUID if you plan on doing Bukkit#getPlayer().

 

Fairly certain they've been in a map for a while, just indexed by name.

Edit: I'm wrong