changes

MapFirstKeyExample/src/com/baeldung/article/HashMapExample.java

@@ -0,0 +1,36 @@
+package com.baeldung.article;
+
+import java.util.AbstractMap;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * @author AshwiniKeshri
+ *
+ */
+public class HashMapExample {
+    public static void main(String[] args) {
+
+        Map<Integer, String> hashmap = new HashMap<>();
+        hashmap.put(5, "A");
+        hashmap.put(1, "B");
+        hashmap.put(2, "C");
+        // hashmap.put(0, "D");
+
+        System.out.println(hashmap);
+
+        Set<Map.Entry<Integer, String>> entrySet = hashmap.entrySet();
+
+        Iterator<Map.Entry<Integer, String>> iterator = entrySet.iterator();
+
+        if (iterator.hasNext())
+            System.out.println("Using Iteraor: " + iterator.next());
+
+        System.out.println("Using Stream: " + entrySet.stream()
+            .findFirst()
+            .orElse(new AbstractMap.SimpleEntry<Integer, String>(-1, "DEFAULT")));
+
+    }
+}

MapFirstKeyExample/src/com/baeldung/article/LinkedHashMapExample.java

@@ -0,0 +1,37 @@
+package com.baeldung.article;
+
+import java.util.AbstractMap;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * @author AshwiniKeshri
+ *
+ */
+public class LinkedHashMapExample {
+
+    public static void main(String[] args) {
+
+        LinkedHashMap<Integer, String> linkedHashMap = new LinkedHashMap<>();
+        linkedHashMap.put(5, "A");
+        linkedHashMap.put(1, "B");
+        linkedHashMap.put(2, "C");
+        // linkedHashMap.put(0, "D");
+
+        System.out.println(linkedHashMap);
+
+        Set<Map.Entry<Integer, String>> entrySet = linkedHashMap.entrySet();
+
+        Iterator<Map.Entry<Integer, String>> iterator = entrySet.iterator();
+
+        if (iterator.hasNext())
+            System.out.println("Using Iterator: " + iterator.next());
+
+        System.out.println("Using Stream: " + entrySet.stream()
+            .findFirst()
+            .orElse(new AbstractMap.SimpleEntry<Integer, String>(0, "DEFAULT")));
+    }
+
+}