Map clear() method in Java with Example Last Updated : 31 Dec, 2018 Comments Improve Suggest changes Like Article Like Report The java.util.Map.clear() method in Java is used to clear and remove all of the elements or mappings from a specified Map collection. Syntax: void clear() Parameters: The method does not accept any parameters. Return Value: The method does not return any value. Below programs are used to illustrate the working of java.util.Map.clear() Method: Program 1: Mapping String Values to Integer Keys. Java // Java code to illustrate the clear() method import java.util.*; public class Map_Demo { public static void main(String[] args) { // Creating an empty Map Map<Integer, String> map = new HashMap<Integer, String>(); // Mapping string values to int keys map.put(10, "Geeks"); map.put(15, "4"); map.put(20, "Geeks"); map.put(25, "Welcomes"); map.put(30, "You"); // Displaying the Map System.out.println("Initial Mappings are: " + map); // Clearing the map using clear() map.clear(); // Displaying the final HashMap System.out.println("Finally the maps look like this: " + map); } } Output: Initial Mappings are: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4} Finally the maps look like this: {} Program 2: Mapping Integer Values to String Keys. Java // Java code to illustrate the clear() method import java.util.*; public class Map_Demo { public static void main(String[] args) { // Creating an empty Map Map<String, Integer> map = new HashMap<String, Integer>(); // Mapping int values to string keys map.put("Geeks", 10); map.put("4", 15); map.put("Geeks", 20); map.put("Welcomes", 25); map.put("You", 30); // Displaying the Map System.out.println("Initial Mappings are: " + map); // Clearing the map using clear() map.clear(); // Displaying the final Map System.out.println("Finally the maps look like this: " + map); } } Output: Initial Mappings are: {4=15, Geeks=20, You=30, Welcomes=25} Finally the maps look like this: {} Note: The same operation can be performed with any type of Mapping with variation and combination of different data types. Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Map.html#clear() Comment More infoAdvertise with us Next Article Map containsKey() method in Java with Examples G gopaldave Follow Improve Article Tags : Java Java-Collections Java-Functions java-map Practice Tags : JavaJava-Collections Similar Reads Map Interface in Java In Java, the Map Interface is part of the java.util package and represents a mapping between a key and a value. The Java Map interface is not a subtype of the Collections interface. So, it behaves differently from the rest of the collection types.Key Features:No Duplicates in Keys: Keys should be un 11 min read Map put() Method in Java with Examples The Map put() method associates the specified value with the specified key in the map. The map put() method is used to insert new key-value pairs inside a map in Java. 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