Share on Google+Share on Google+

SCJP Module-9 Question-5

Advertisement
The Sample program given below will check your understanding of ConcurrentSkipListMap in Collection framework.

Given below the sample code :

import java.util.NavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;
public class CheckSize {
public static void main(String... args) {
NavigableMap <Integer, String>nM = new ConcurrentSkipListMap<Integer, String>();
nM.put(4, "Wednesday");
nM.put(5, "Thursday");
nM.put(6, "Friday");
nM.put(1, "Sunday");
nM.put(2, "Monday");
System.out.print(nM.ceilingKey(3));
}}

What will be the output of the above ?

1. Compile error

2. 2

3. null

4. 4

Answer

(4)

Explanation

ceilingKey() : Returns the least key greater than or equal to the given key, or null if there is no such key.

Advertisements

Posted on: July 16, 2010 If you enjoyed this post then why not add us on Google+? Add us to your Circles

Share this Tutorial Follow us on Twitter, or add us on Facebook or Google Plus to keep you updated with the recent trends of Java and other open source platforms.