Generics
in Java is one of important feature added in Java 5 along with Enum, autoboxing
and varargs , to provide compile time type-safety
Generics notations and naming conventions
Generic Term
|
Meaning
|
Set<E>
|
Generic Type , E is called formal parameter
|
Set<Integer>
|
Parametrized type , Integer is actual parameter here
|
<T extends Comparable>
|
Bounded type parameter
|
<T super Comparable>
|
Bounded type parameter
|
Set<?>
|
Unbounded wildcard
|
<? extends T>
|
Bounded wildcard type
|
<? Super T>
|
Bounded wildcards
|
Set
|
Raw type
|
<T extends Comparable<T>>
|
Recursive type bound
|
T – used to denote type
E – used to denote element
K – keys
V - values
N – for numbers
Exampl
public class GenericVsArray
{
public static void main(String args[])
public static void main(String args[])
{
Holder<Integer> numbers = new Holder<Integer>(10);
numbers.add(101);
System.out.println("Get: " + numbers.get(0));
}
}
