The syntax for specifying the type of elements in a collection:
CollectionClass<Type> collectionName = new CollectionClass<Type>();
Example 1: A statement that creates an arraylist of type String:
ArrayList<String> codes = new ArrayList<String>();
Example 2: A statement that creates an array list of intergers:
ArrayList<Interger> codes = new ArrayList<Interger>();
Example 3: Code that creates a linked list of type Prouct:
LinkedList<Product> products; proucts = new LinkedList<Product>();
The syntax for declaring a class that uses generic types:
public class ClassName<TypeVariable [ , TypeVariable ] . . . >{}
Example 4: A class statement for a class that implements a queue
public class GenicrQueue<E>{}
Descriptions:
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Create typed collections. A typed collection is a collection that can hold only objects of a certain type.
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To declare a variable that refers to a typed collection, you list the type in angle brackets (<>) follwing the name of the collection class.
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The type variable can not be a primitive type such as int or double. It can use the wrapper class like Interger, Double and user defined classes.
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If you do not specify a type for a collection, the collection can hold any type of object.