hash map operations in java

Author: NirmalSilwal

CodingBlocks Training/Day23/HashMapDemo.java

@@ -0,0 +1,39 @@
+package Lecture23;
+
+import java.util.HashMap;
+
+public class HashMapDemo {
+
+	public static void main(String[] args) {
+		
+		HashMap<String, Integer> map = new HashMap<String, Integer>();
+
+		map.put("Nepal", 100);
+		map.put("USA", 200);
+		map.put("India", 250);
+		map.put("Denmark", 300);
+
+		System.out.println(map);
+
+		System.out.println(map.get("Nepal")); // 100
+
+		System.out.println(map.remove("India")); // 250
+		System.out.println(map);
+
+		System.out.println(map.containsKey("China"));
+		System.out.println(map.containsKey("USA"));
+
+		System.out.println(map.remove("China")); // null
+	}
+
+}
+
+/* output:
+{USA=200, Denmark=300, Nepal=100, India=250}
+100
+250
+{USA=200, Denmark=300, Nepal=100}
+false
+true
+null
+*/