In this section, you will see how to get key and value of HashMap in java.

How to get key and value of HashMap in java.

The HashMap extends AbstractMap and implements Map interface. It is available in java.util package. It stores value in the form of key/values pair. The put(key,value) method is used for adding entry in map.

entrySet()-- It is a method of HashMap class.  Returns a Set of entries(Key/Value) of corresponding map.
getKey()-- It is a method of Map.Entry interface. Returns key of corresponding entry.
getValue()-- It is a method of Map.Entry interface. Returns value of corresponding entry.

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class AccessKeyValueOfHashMap {
	public static void main(String[] args) {
		// Create a Empty HashMap 
		HashMap<String, String> obHashMap = new HashMap<String, String>();
		// Put values in hash map
		obHashMap.put("AB", "1");
		obHashMap.put("EF", "2");
		obHashMap.put("Gh", "3");
		obHashMap.put("CD", "4");
		//Store entry (Key/Value)of HashMap in set
		Set mapSet = (Set) obHashMap.entrySet();
		//Create iterator on Set 
		Iterator mapIterator = mapSet.iterator();
		System.out.println("Display the key/value of HashMap.");
		while (mapIterator.hasNext()) {
			Map.Entry mapEntry = (Map.Entry) mapIterator.next();
			// getKey Method of HashMap access a key of map
			String keyValue = (String) mapEntry.getKey();
			//getValue method returns corresponding key's value
			String value = (String) mapEntry.getValue();
			System.out.println("Key : " + keyValue + "= Value : " + value);
		}
	}
}

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