SCJP Module-9 Question-4


 

SCJP Module-9 Question-4

The program given below will check your understanding of NavigableMap, ConcurrentSkipListMap and how the ConcurrentSkipListMap is object is created.

The program given below will check your understanding of NavigableMap, ConcurrentSkipListMap and how the ConcurrentSkipListMap is object is created.

Given below the sample code :

import java.util.NavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;
public class Check {
public static void main(String... args) {
NavigableMap <Integer, String>nM = new ConcurrentSkipListMap<Integer, String>();
System.out.print(nM.lastEntry());
}
}

What will be the output of the code ?

1. Compile error

2. It throws exception

3. null

4. 0

Answer

(3)

Explanation

lastEntry()   Returns a key-value mapping associated with the greatest key in this map, or null if
the map is empty.

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