Checking how many objects in a HashMap have the same value

I'm saving a two players into a HashMap but i'm not sure on how to check on how many values of those are the same, for example:

Code:java

map.put("x", "y");
map.put("g", "y");
map.put("e", "r");
map.put("k", "y");

So when i call my method getSameValues() which takes a value so if i did it getSameValues("y") it should return 3 as a int. But i have not clue on how i compare Hash Map Values with each other.

 

MCCoding
map.values()

 

MCCoding
Iterate through the map and increment an int if the values match up. For example:

Code:java

    private HashMap<String, String> map = new HashMap<String, String>();
    private int valueCount;
 
    public int getSameValues(String value){
        for (String s : map.values()){
            if (value.equals(map.get(s)))
                valueCount++;
        }
        return valueCount;
    }

 

The Gaming Grunts

Thanks for the help but when i try to get the value it returns 0. here is what i have

Code:java

player.sendMessage(getSameValues(player.getName()));

and it returns 0, my value in my HashMap is MCCoding and the value i'm adding is MCCoding. the values it's spitting out when i add a print line to the for loop in getSaveValues are MCCoding, MCCoding, that23 so it should return 2 not 0, know why this may happen?

 

The Gaming Grunts
-_-
map.get(s);
You're iterating the values, why would you be getting anything? just value.equalsIgnoreCase(s);

 

The Gaming Grunts Yes, that absolutely needed to be a field, and nothing will go wrong with it like that.

 

AdamQpzm
So how do I do it now?

 

EDIT MCCoding Also, local variable, not field.

 

when you store objects, you also can store number of instances inside referse lookup table.

 

AdamQpzm
Ah thanks for that git it all working!

 

MCCoding
Sorry. There's also a .matches() that you could use. For example:

Code:java

    private static HashMap<String, String> map = new HashMap<String, String>();
    private static int valueCount;
 
    public static void main(String[] args){
        map.put("doge", "test");
        map.put("derp", "test");
        map.put("herp", "test1");
        map.put("hello", "bye");
        System.out.println(getSameValues("test"));   
    }
 
    public static int getSameValues(String value){
        for (String s : map.values()){
            if (value.matches(s))
                valueCount++;
        }
        return valueCount;
    }

That will print out 2, as there are 2 values in the map that match "test".

 

you code will provide valid output only once.
The Gaming Grunts

 

The Gaming Grunts Every variable that could possibly be a field there, is a field! Amazing.

 

The Gaming Grunts
#matches() checks if the string matches the given regex.

 

Code:java

Collections.frequency(map.values(), "needle")

Anyone?

 

If not that, it's a simple re-mapping:

Code:java

public <T> Map<T, Integer> getValueOccurances(Map<?, T> original) {
    Map<T, Integer> back = new HashMap<>();
    for (T val : original.values()) {
        if (back.containsKey(val)) {
            back.put(val, back.get(val) + 1);
        } else {
            back.put(val, 1);
        }
    }
    return back;
}