Added InnerClasses

54-AnonymousObjects/54-AnonymousObjects.iml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
   <component name="NewModuleRootManager">
-    <output url="file://$MODULE_DIR$/out/production/" />
+    <output url="file://$MODULE_DIR$/out/production" />
     <output-test url="file://$MODULE_DIR$/../out/test/54-AnonymousObjects" />
     <exclude-output />
     <content url="file://$MODULE_DIR$">

55-InnerClasses/55-InnerClasses.iml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager">
+    <output url="file://$MODULE_DIR$/out/production/" />
+    <output-test url="file://$MODULE_DIR$/../out/test/55-InnerClasses" />
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

55-InnerClasses/src/Main.java

@@ -0,0 +1,19 @@
+public class Main {
+    public static void main(String[] args) {
+
+        /*inner class - A class inside another class.
+       Useful if a class should be limited in scope.
+       Usually private, but not necessary.
+       Helps group classes that belong together.
+       Extremely useful for listeners for specific events.
+       Precursor for anonymous inner classes
+        */
+
+        Outside out = new Outside();
+        Outside.Inside inside = out.new Inside();
+
+        System.out.println(out.x + inside.y);
+
+        inside.greeting();
+    }
+}

55-InnerClasses/src/Outside.java

@@ -0,0 +1,13 @@
+public class Outside {
+
+    String x = "Hello ";
+
+    public class Inside {
+
+        String y = "World";
+
+        public void greeting() {
+            System.out.println(x + y);
+        }
+    }
+}