diff --git a/Java/LearnHashMap.java b/Java/LearnHashMap.java
new file mode 100644
index 0000000..f0b5507
--- /dev/null
+++ b/Java/LearnHashMap.java
@@ -0,0 +1,31 @@
+import javax.swing.text.html.parser.Entity;
+import java.util.*;
+public class LearnHashMap
+{
+    public static void main(String[] args) {
+        Map<String,Integer> numbers = new HashMap<>();
+        numbers.put("one",1);
+        numbers.put("five",5);
+        numbers.put("two",2);
+        numbers.put("three",3);
+
+        //numbers.put("two",22); ------> override the old value
+        //numbers.putIfAbsent("two",22);
+
+        System.out.println(numbers);
+        for(Map.Entry<String,Integer> e: numbers.entrySet()){
+            System.out.println(e);
+        }
+//        for(Map.Entry<String,Integer> e: numbers.entrySet()){
+//            System.out.println(e.getKey());
+//            System.out.println(e.getValue());
+//        }
+        for(String key: numbers.keySet()){
+            System.out.println(key);
+        }
+        System.out.println(numbers.containsKey("one"));
+
+        numbers.replace("one",1,11);
+        System.out.println(numbers);
+    }
+}