Type inference doesn't seem to work for arrays with generic methods? I receive the error 'The method contains(T[], T) is not applicable for the arguments (int[], int)'. How should I be doing this?
method(new int[1], 0); //Error
...
public static <T> void method(T[] array, T value) {
//Implement
}
Generics doesn't work with primitive types, only with object types.
You can do what looks like using generics with primitive types, due to auto-boxing:
<T> void methodOne(T value) {}
methodOne(1); // Compiles OK, T = Integer.
What is actually happening here is that the int literal 1 is being "boxed" to Integer.valueOf(1), which is an object of type Integer.
You can pass also an int[] to a generic method, because int[] is an object type itself. So:
methodOne(new int[1]); // Compiles OK, T = int[].
However, you can't mix these two with the same type variable: int[] and Integer are not related types, so there is no single type variable T which is satisfied by both parameters. There is no equivalent auto-boxing operator from int[] to Integer[].
As such, you would need to pass an Integer[] array as the first parameter:
method(new Integer[1], 0);
You could use Integer instead of int, since generics don't work with primitive types.
why use primitive type here. Generics only work with referenced type.
method(new int[1], 0); //Error
better to go with
method(new Integer[]{1,2,3,4}, 0); //works fine
new Integer[1], 0instead.Double,Integer,Boolean,... is created in Java.public static void method(Object[] array, Object value)