fix(guide): simplify directory structure

guide/english/java/final-keyword/index.md

@@ -0,0 +1,58 @@
+---
+title: Final
+---
+
+## final
+You use the `final` keyword to mark a variable constant, so that it can be assigned only once. So you must initialize a final variable with a value. If its not initialized (when declared, inside Constructor or inside static blocks), compile time error will occur.
+
+***Example:***
+```java
+class MyClass {
+  public static final double PI = 3.14;
+  public static void main(String[] args){
+    System.out.println(PI);
+  }
+}
+```
+PI is now a constant. Any attempt to assign it a value will cause an error.
+
+-----------------------------------------------------------------------------------------
+If you make any method as final, you cannot override it.
+```java
+class Bike{  
+  final void run(){System.out.println("running");}  
+}  
+     
+class Honda extends Bike{  
+   void run(){System.out.println("running safely with 100kmph");}  
+     
+   public static void main(String args[]){  
+   Honda honda= new Honda();  
+   honda.run();  
+   }  
+}  
+```
+
+Output wil be - 
+  Output:Compile Time Error
+  
+---------------------------------------------------------------------------------------
+
+
+If you make any class as final, you cannot extend it.
+  
+```java
+final class Bike{}  
+  
+class Honda1 extends Bike{  
+  void run(){System.out.println("running safely with 100kmph");}  
+    
+  public static void main(String args[]){  
+  Honda1 honda= new Honda();  
+  honda.run();  
+  }  
+}
+```
+
+Output will be-
+ Output:Compile Time Error