Libgdx - How to get a specific item from an array? - arrays

Question

I have a Player class which has
int number;
In main, I store them in Array.
Array<Player> players;
How can I get a player which has for example number=2?

Answer 1

This question is programming in general, and has several ways to do what you say, I recommend you look for OOP.
a solution, general, would encapsulate the variable, "creating getter and setter, you need, eg:
this a simple class;
private int number;
public Player(int num){
this.number = num;
}
public int getNumber (){
return number;
}
public void setNumber (int n){
this.number = n;
}
.
In your code for search you can use the solution, using a for, or an iterator
for (int a = 0; a < players.size(); a++){
int tmpNumber = players.get(a).getNumber();
if(tmpNumber == 2){
players.get(a); //the object array with index equal to
//the value of 'a', have, number 2 stored
//in the variable 'number'
}
}
but this question I think is a little matter of taste or needs you have

Answer 2

I'm going to make some assumptions to demonstrate it:
Let's assume you have a constructor in your Player class:
public Player(int num){
this.number = num;
}
And you have added some players in your arraylist:
players.add(new Player(1));
players.add(new Player(2));
players.add(new Player(3));
Now loop through your array and find the one where number == 2
for (int i = 0; i < players.size(); i++){
Player tmp = players.get(i);
if(tmp.number == 2){
System.out.println("Index of player number 2: " + players.indexOf(tmp));
}
}

Answer 3

I realised that I'd misunderstood the question with my previous answer. Here's a better one...
Those recommending you iterate through the Array are correct, but if you have a lot of Players this will be ineffeicient. In that case, it would be better to use a Map where the key was the player number, and the value is the player itself.
Here's some sample code showing the approach (most of it is just setting up some test data)...
import java.util.HashMap;
import java.util.Map;
public class Temp {
public static void main(String[] args) {
// Create a map instead of an array
Map<Integer, Player> players = new HashMap<>();
// Quick hack just to put some data in it.
for(int i = 0; i < 1000; i++) {
players.put(i, new Player(i));
}
// Once they're in a map, retrieving them is simple...
Player playerFromMap = players.get(537);
// Check we got it right
System.out.println(playerFromMap.getNumber()); // 537
}
private static class Player {
private int number;
private Player(int number) {
this.number = number;
}
public int getNumber() {
return number;
}
}
}