Enthuware

This cant convince me i think the ceiling and higher is the same ,,.. or what

aaa --> higher b as question
so isnt
aaa --> ceiling b too but in the question its not

why

bb --> higher c as question
so isnt
bb -->ceiling is c too ?

E ceiling(E e)
Returns the least element in this set greater than or equal to the given element, or null if there is no such element.
E floor(E e)
Returns the greatest element in this set less than or equal to the given element, or null if there is no such element.
E higher(E e)
Returns the least element in this set strictly greater than the given element, or null if there is no such element.
E lower(E e)
Returns the greatest element in this set strictly less than the given element, or null if there is no such element.


Note that methods of NavigableMap (such as ceilingEntry(), ceilingKey(), floorEntry(), floorKey() etc.) also work exactly the same way.

ceiling and higher are not same. Kindly read their descriptions. In some cases, they may return same values but not in all.
System.out.println(ns.higher("bb")); //prints c
System.out.println(ns.ceiling("bb")); //prints bb

admin wrote:ceiling and higher are not same. Kindly read their descriptions. In some cases, they may return same values but not in all.
System.out.println(ns.higher("bb")); //prints c
System.out.println(ns.ceiling("bb")); //prints bb

ok but what is the rule here in this example please



http://s14.postimg.org/6t1xswti9/cielling.jpg

I am sorry I didn't understand your question. Rule is same for this question. Higher and ceiling are different methods and work differently.

"Returns the least element in this set greater than ... " - the explanation is formally correct but from the other hand it seems it is made to confuse.

I offer followed just to easy remembering:

higher - higher (greater)
ceiling - higher or equal

lower - lower (smaller)
floor - lower or equal

NavigableSet<String> myStringSet = new TreeSet<String>();
myStringSet.add("a");
myStringSet.add("aa");
myStringSet.add("b");
myStringSet.add("bb");
myStringSet.add("c");
myStringSet.add("cc");
System.out.println();
System.out.println(myStringSet);
System.out.println("TreeSet.ceiling(): " + myStringSet.ceiling("a"));
System.out.println("TreeSet.higher(): " + myStringSet.higher("a"));

Output:
[a, aa, b, bb, c, cc]
TreeSet.ceiling(): a
TreeSet.higher(): aa

doesn't seem right to me? how is aa higher than higher("a")?

>>how is aa higher than higher("a")?

Not sure what you mean. Can you please clarify your question?