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Exploring the new Collection APIs to be introduced in Java 8
import java.util.*;
public class EnhancedCollections{
public static void main(String[] args){
List<Integer> counts = new ArrayList<Integer>();
for(int i=1;i <= 10; i++){
counts.add(i);
}
//Using external iterators
System.out.println("Using external iterator");
for(Integer i : counts){
System.out.print(i+" ");
}
System.out.println();
//Using internal iterators
System.out.println("Using internal iterator");
counts.forEach(i -> {System.out.print(i*2+" ");});
System.out.println();
//Printing only Even numbers- Using external iterator
System.out.println("Printing Even numbers- Using External iterator");
for ( Integer i : counts){
if ( i % 2 == 0 ){
System.out.print(i+" ");
}
}
System.out.println();
System.out.println("Printing Even numbers- Using Internal iterator");
counts.filter(i -> i%2 == 0)
.forEach(i-> {System.out.print(i+" ");});
System.out.println();
System.out.println("Odd numbers doubled, a new list created-"+
"Using external Iterator");
List<Integer> newCounts = new ArrayList<Integer>();
for(Integer i : counts){
if ( i % 2 != 0 ){
newCounts.add(i*2);
}
}
for(Integer i : newCounts){
System.out.print(i+" ");
}
System.out.println();
System.out.println("Odd numbers doubled, a new list created-"+
"Using internal Iterator");
List<Integer> newCountsNew = new ArrayList<Integer>();
counts.filter(i -> i % 2 != 0)
.map(i -> i*2)
.into(newCountsNew);
newCountsNew.forEach(i -> {System.out.print(i+" ");});
System.out.println();
}
}
@qnoid

@sanaulla123 which build of Java 8 are you using for the above example Mohamed? b82 doesn't seem to have support for it.

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