Program
import java.util.Iterator;
import java.util.TreeSet;
public class TreesetWithMethods
{
public static void main(String[] args)
{
TreeSet<String> tree1 = new TreeSet<String>();
tree1.add("Sun");
tree1.add("Micro");
tree1.add("System");
System.out.println("TreeSet :" + tree1);
System.out.println("");
TreeSet<String> tree2 = new TreeSet<String>();
tree2.add("developed");
tree2.add("java");
//addAll(Collection<? extends E> c)
tree1.addAll(tree2);
System.out.println("1. After addAll :" + tree1);
System.out.println("");
//remove(Object o)
System.out.println("2. boolean remove 'developed' :" + tree1.remove("developed"));
System.out.println("After Remove :" + tree1);
System.out.println("");
TreeSet<String> treeHeadSet = new TreeSet<String>();
//headSet(E toElement)
treeHeadSet = (TreeSet) tree1.headSet("java");
System.out.println("3. After Headset :" + treeHeadSet);
Iterator iterator;
//iterator()
iterator = tree1.iterator();
System.out.println("");
System.out.println("4 . Iterator For Ascending");
while (iterator.hasNext())
{
System.out.println(iterator.next() + " ");
}
TreeSet<String> treeReverse = new TreeSet<String>();
treeReverse = (TreeSet) tree1.descendingSet();
//descendingIterator()
Iterator iterator2;
iterator2 = treeReverse.iterator();
System.out.println("");
System.out.println("5 . Iterator For decending");
while (iterator2.hasNext())
{
System.out.println(iterator2.next() + " ");
}
}
}Output
TreeSet :[Micro, Sun, System] 1. After addAll :[Micro, Sun, System, developed, java] 2. boolean remove 'developed' :true After Remove :[Micro, Sun, System, java] 3. After Headset :[Micro, Sun, System] 4 . Iterator For Ascending Micro Sun System java 5 . Iterator For decending java System Sun Micro
Description
public boolean addAll(Collection c)
Adds all of the elements in the specified collection to this set.
Specified by:
addAll in interface Collection
Specified by:
addAll in interface Set
Overrides:
addAll in class AbstractCollection
Parameters:
c – collection containing elements to be added to this set
Returns:
true if this set changed as a result of the call
Throws:
ClassCastException – if the elements provided cannot be compared with the elements
currently in the set
NullPointerException – if the specified collection is null or if any element is null and this set
uses natural ordering, or its comparator does not permit null elements
public boolean remove(Object o)
Removes the specified element from this set if it is present. More formally, removes an element e such
that Objects.equals(o, e), if this set contains such an element. Returns true if this set contained the
element (or equivalently, if this set changed as a result of the call). (This set will not contain the element
once the call returns.)
Specified by:
remove in interface Collection
Specified by:
remove in interface Set
Overrides:
remove in class AbstractCollection
Parameters:
o – object to be removed from this set, if present
Returns:
true if this set contained the specified element
Throws:
ClassCastException – if the specified object cannot be compared with the elements currently in this set
NullPointerException – if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements
public SortedSet headSet(E toElement)
Description copied from interface: NavigableSet
Returns a view of the portion of this set whose elements are strictly less than toElement. The returned set is backed by this set, so changes in
the returned set are reflected in this set, and vice-versa. The returned set supports all optional set operations that this set supports.
The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.
Equivalent to headSet(toElement, false).
Specified by:
headSet in interface NavigableSet
Specified by:
headSet in interface SortedSet
Parameters:
toElement – high endpoint (exclusive) of the returned set
Returns:
a view of the portion of this set whose elements are strictly less than toElement
Throws:
ClassCastException – if toElement is not compatible with this set’s comparator (or, if the set has no comparator if toElement does not implement Comparable). Implementations may, but are not required to, throw this exception if toElement cannot be compared to elements currently in the set.
NullPointerException – if toElement is null and this set uses natural ordering, or its comparator does not permit null elements
IllegalArgumentException – if this set itself has a restricted range, and toElement lies outside the bounds of the range
public Iterator iterator()
Returns an iterator over the elements in this set in ascending order.
Specified by:
iterator in interface Collection
Specified by:
iterator in interface Iterable
Specified by:
iterator in interface NavigableSet
Specified by:
iterator in interface Set
Specified by:
iterator in class AbstractCollection
Returns:
an iterator over the elements in this set in ascending order
public Iterator descendingIterator()
Returns an iterator over the elements in this set in descending order.
Specified by:
descendingIterator in interface NavigableSet
Returns:
an iterator over the elements in this set in descending order
