How use a generic type in constructor of class (Java)

Question

I'm looking for a way to allow the constructor of this class take in an array of a generic type.

public class my
{

   public my(T[] arr)  // how resolve this
   {
      ...
   }
}

Answer 1

There are two ways for you to have a type array as a parameter in your constructor. One, you can add the parameter to the class like so...

public class my<T> {

   public my(T[] arr)
   {
        ...
   }

}

Or, your constructor can take in a Type Parameter, like so:

public class my {

   public <T> my(T[] arr)
   {
      ...
   }
}

You can initialize an object of the first class like so:

my<SomeClass> varName = new my<>(arrayOfSomeClass);

And you can initialize an object of the second class like so:

my varName = new <SomeClass>my();

Hope this helps!

Answer 2

I can't think of any situation where I would want a generic constructor in a non-generic class. But hey, here you go:

You just add <T> to the constructor declaration:

public <T> my(T[] arr) {

}

Be careful when you call this constructor. Because it is generic, you can't use primitive types like int or char. You need to use their reference type counterparts, Integer and Character.