AbstractMap keySet() Method in Java with Examples Last Updated : 26 Oct, 2018 Comments Improve Suggest changes Like Article Like Report The AbstractMap.keySet() method in Java is used to create a set out of the key elements contained in the abstract map. It basically returns a set view of the keys or we can create a new set and store the key elements in them. Syntax: AbstractMap.keySet() Parameters: The method does not take any parameter. Return Value: The method returns a set having the keys of the abstract map. Below programs are used to illustrate the working of AbstractMap.keySet() Method: Program 1: Mapping String Values to Integer Keys. Java // Java code to illustrate the keySet() method import java.util.*; public class Abstract_Map_Demo { public static void main(String[] args) { // Creating an empty AbstractMap AbstractMap<Integer, String> abs_map = new HashMap<Integer, String>(); // Mapping string values to int keys abs_map.put(10, "Geeks"); abs_map.put(15, "4"); abs_map.put(20, "Geeks"); abs_map.put(25, "Welcomes"); abs_map.put(30, "You"); // Displaying the AbstractMap System.out.println("Initial Mappings are: " + abs_map); // Using keySet() to get // the set view of keys System.out.println("The set is: " + abs_map.keySet()); } } Output: Initial Mappings are: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4} The set is: [20, 25, 10, 30, 15] Program 2: Mapping Integer Values to String Keys. Java // Java code to illustrate the keySet() method import java.util.*; public class Abstract_Map_Demo { public static void main(String[] args) { // Creating an empty AbstractMap AbstractMap<String, Integer> abs_map = new HashMap<String, Integer>(); // Mapping int values to string keys abs_map.put("Geeks", 10); abs_map.put("4", 15); abs_map.put("Geeks", 20); abs_map.put("Welcomes", 25); abs_map.put("You", 30); // Displaying the AbstractMap System.out.println("Initial Mappings are: " + abs_map); // Using keySet() to get the set view of keys System.out.println("The set is: " + abs_map.keySet()); } } Output: Initial Mappings are: {4=15, Geeks=20, You=30, Welcomes=25} The set is: [4, Geeks, You, Welcomes] Note: The same operation can be performed with any type of Mappings with variation and combination of different data types. Comment More infoAdvertise with us Next Article AbstractMap keySet() Method in Java with Examples C chinmoy lenka Follow Improve Article Tags : Misc Java Java-Collections Java - util package Java-Functions Java-AbstractMap +2 More Practice Tags : JavaJava-CollectionsMisc Similar Reads AbstractMap put() Method in Java with Examples The AbstractMap put() method inserts a mapping into an AbstractMap. This means we can add a specific key and its value, into a particular map. If an existing key is passed, then the previous value gets replaced by the new value. If a new pair is passed, then the pair gets inserted as a whole. Exampl 3 min read AbstractMap get() Method in Java with Examples The AbstractMap.get() method of AbstractMap class is used to retrieve or fetch the value mapped by a particular key mentioned in the parameter. It returns NULL when the map contains no such mapping for the key. Syntax: AbstractMap.get(Object key_element) Parameter: The method takes one parameter key 2 min read AbstractMap remove() Method in Java with Examples The AbstractMap.remove() is an inbuilt method of AbstractMap class and is used to remove the mapping of any particular key from the map. It basically removes the values for any particular key in the Map. Syntax: AbstractMap.remove(Object key) Parameters: The method takes one parameter key whose mapp 2 min read AbstractMap values() Method in Java with Examples The AbstractMap.values() method of AbstractMap class in Java is used to create a collection out of the values of the map. It basically returns a Collection view of the values in the AbstractMap. Syntax: AbstractMap.values() Parameters: The method does not accept any parameters. Return Value: The met 2 min read AbstractMap entrySet() Method in Java with Examples The AbstractMap.entrySet() method in Java is used to create a set out of the same elements contained in the map. It basically returns a set view of the abstract map or we can create a new set and store the map elements into them. Syntax: AbstractMap.entrySet() Parameters: The method does not take an 2 min read Like