What types can we assign to K in HashMap<K,V>? Is it only numeric types (int, float) or we can assign user defined objects?
What types can we assign to K in HashMap<K,V> ? Is it only numeric
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What types can we assign to K in HashMap<K,V>? Is it only numeric types (int, float) or we can assign user defined objects?
You can use any type as long as it has sane
equals()andhashCode()implementations.Strictly speaking: you can use any reference type, but it won’t work as expected if the type doesn’t have sane implementations of those methods.
Note that you can not use the primitive types (
int,float, …) but can use their wrapper types instead (Integer,Float, …). This is because generics can only handle reference types.