The keySet() method of SortedMap Interface in Java is used to create a set out of the key elements contained in the treemap. It basically returns a set view of the keys or we can create a new set and store the key elements in them in an ascending order. Since the set is backed by the map, any changes made to the map are reflected in the set, and vice-versa.
Parameters: The method does not take any parameter.
Return Value: The method returns a set having the keys of the treemap in ascending order.
Below programs are used to illustrate the working of the above method:
Program 1: Mapping String Values to Integer Keys.
Program 2: Mapping Integer Values to String Keys.
Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.
Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.