Code to create responsive navigation bar with dropdown menu using bootstrap

Creating responsive navigation bar with dropdown menu in bootstrap is very simple. It is as easy to customize as to create it. Below is a running code for creating navigation bar(Menus) using bootstrap.
<!-- navbar with dropdown menu -->
<div class="navbar navbar-default navbar-fixed-top"> //creating fixed navbar menu you can change fixed to static
<div class="container">
<div class="navbar-header">