package org.kodejava.example.intro;
import java.util.Map;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;
public class TypeSpecificCollection {
public static void main(String[] args) {
//
// Using a Generic can enable us to create a type specific collection
// object. In the example below we create a Map whose key is an Integer
// a have the value of a String.
//
Map grades = new HashMap();
grades.put(1, "A");
grades.put(2, "B");
grades.put(3, "C");
grades.put(4, "D");
grades.put(5, "E");
//
// A value obtained from type specific collection doesn't not need to
// be casted, it knows the type returned.
//
String value = grades.get(1);
//
// Creating a List that will contains a String only values.
//
List dayNames = new ArrayList();
dayNames.add("Sunday");
dayNames.add("Monday");
dayNames.add("Tuesday");
dayNames.add("Wednesday");
//
// We also don't need to cast the retrieved value because it knows the
// returned type object.
//
String firstDay = dayNames.get(0);
}
}
dimanche 6 mai 2012
How do I create type specific collections?
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