Hashmap with specific key type but any value type in function parameters

Asked Mar 29 '18 at 06:10

Active Mar 29 '18 at 06:10

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Is there a clean way to take in a hashmap as a function parameter with a specific key type, but any value type?

E.g. I have a few hashmaps with Integer as the key but each uses a different object for the values and I want to create a function they can share. I was thinking something like this but it won't allow me to pass my hashmaps in as they have a more specific value type than Object

public static int getUnusedId(Map<Integer, Object> map){

asked Mar 29 '18 at 06:10

Dominic Mortlock

Welcome to StackOverFlow.same way which you have specified. – Lova Chittumuri Mar 29 '18 at 06:13
2

getUnusedId(Map map) – JB Nizet Mar 29 '18 at 06:14
I am unable to pass in a hashmap created like so however "HashMap map" – Dominic Mortlock Mar 29 '18 at 06:15
Thanks JB Nizet that was perfect. Can you post it as an answer so I can approve? – Dominic Mortlock Mar 29 '18 at 06:16
OP, you're looking for generics. https://docs.oracle.com/javase/tutorial/java/generics/methods.html Since I stupidly can't post an answer since the question was closed, I'll put it into a comment: public static int getUnusedId(final Map map) {} public static void main(final String[] args) { final Map map = new HashMap<>(); System.err.println(getUnusedId(map));} – Dreamspace President Mar 29 '18 at 06:20

Hashmap with specific key type but any value type in function parameters

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