Declare Setdouble - JAVA

The sets, which implement the interface Collection of Java , as ArrayList, LinkedList, HashSet, etc... do not accept primitive types.

But nothing prevents you from declaring a Set<Double> seuSet and then doing seuSet.add(2.33) , a primitive double. Java uses Wrappers or wrappers when this happens.

Every primitive type in java has a corresponding Wrapper :

int => Integer
long => Long
float => Float
double => Double
... assim por diante...

So when you try to add a primitive double to the array by doing seuSet.add(2.33) , Java actually executes the following: seuSet.add(new Double(2.33))

And for what you're wanting, which is to take an average of the numbers, I see no problem doing so.

In fact, you can not use primitive types in Collections of Java.

If you want to work with double and Set , for your case, the alternatives are:

• Use any library that provides collections implemented with primitive types, such as Trove or HPPC ;
• Make your own implementation:);
• Use Set<Double> same, if double primitive is not an obligation;