The headSet() method of
NavigableSet interface in Java is used to return a view of the portion of this set whose elements range from
fromElement to
toElement.
- If fromElement and toElement are equal, the returned set is empty unless fromInclusive and toInclusive are both true.
- 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.
Note: The returned set will throw an IllegalArgumentException on an attempt to insert an element outside its range.
Syntax:
NavigableSet<E> subSet( E fromElement,
boolean fromInclusive,
E toElement,
boolean toInclusive);
Where, E is the type of elements maintained by this Set container.
Parameters: This function accepts 4 parameters as explained below:
- fromElement: This is a mandatory parameter and specifies the low end point of the returned set.
-
fromInclusive: This is an optional parameter and is of boolean type. If this is set to True, then low end point will be included in the returned view otherwise not.
- toElement: his is a mandatory parameter and specifies the high end point of the returned set.
- toInclusive: This is optional parameter and is of boolean type. If this is set to True, then low end point will be included in the returned view otherwise not.
Return Value: It returns a view of the portion of this set whose elements range from fromElement to toElement.
Below programs illustrate the subSet() method in Java:
Program 1: NavigableSet with integer elements.
Output:
Map with key-value between the given argument : [1, 2, 3, 4, 5]
Map with key-value between the given argument : [2, 3, 4, 5]
Program 2: NavigableSet with string elements.
