Smooth scroll Javascript

script.js

jQuery(document).ready(function ($) {
	'use strict';

	// Smooth scroll
	// https://css-tricks.com/snippets/jquery/smooth-scrolling/
	// Select all links with hashes
	$('a[href*="#"]')
		// Remove links that don't actually link to anything
		.not('[href="#"]')
		.not('[href="#0"]')
		.click(function(event) {
			// On-page links
			if ( location.pathname.replace(/^\//, '') === this.pathname.replace(/^\//, '') && location.hostname === this.hostname ) {
				// Figure out element to scroll to
				var target = $(this.hash);
				target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
				
				// Does a scroll target exist?
				if (target.length) {
					// Only prevent default if animation is actually gonna happen
					event.preventDefault();
					
					$('html, body').animate({
						scrollTop: target.offset().top
					}, 1000, function() {
						// Callback after animation
						// Must change focus!
						var $target = $(target);
						
						$target.focus();
						if ($target.is(":focus")) { // Checking if the target was focused
							return false;
						} else {
							$target.attr('tabindex','-1'); // Adding tabindex for elements not focusable
							$target.focus(); // Set focus again
						}
					});
				}
			}
		});
});