Mock Exams – NavigableMap

2) What will be the output of the following program?

 package navmap; import java.util.HashMap; import java.util.NavigableMap; import java.util.TreeMap; public class Ques01 { public static void main(String[] args) { NavigableMap<String, String> colors = new HashMap<String, String>(); colors.put("RED", "Red"); colors.put("BLUE", "Blue"); System.out.println(colors.get("BLUE")); } } 

1. The program will output ‘null’.
2. The program will return ‘Blue’.
3. The program won’t compile because of compilation errors.
4. The program will throw a run-time exception.

Answer

2) c.

The program won’t compile since the class HashMap doesn’t implement the NavigableMap interface.