Get keys from HashMap in Java

Question

I have a Hashmap in Java like this:

private Map team1 = new HashMap();

Then I fill it like th

Answer 1

What I'll do which is very simple but waste memory is to map the values with a key and do the oposite to map the keys with a value making this:

private Map team1 = new HashMap();

it's important that you use so you can map keys:Value and Value:Keys like this

team1.put("United", 5);

team1.put(5, "United");

So if you use team1.get("United") = 5 and team1.get(5) = "United"

But if you use some specific method on one of the objects in the pairs I'll be better if you make another map:

private Map team1 = new HashMap();

private Map team1Keys = new HashMap();

and then

team1.put("United", 5);

team1Keys.put(5, "United");

and remember, keep it simple ;)