Smooth scrolling effect, can be used for Bootstrap 4 navigation. Requires a full version of jQuery in order for this to work. (jquery.slim is insufficient)

scroll.js

$(function() {
  var topoffset = 70; //variable for menu height

  //Use smooth scrolling when clicking on navigation
  $('.navbar-nav a').click(function() {
    if (location.pathname.replace(/^\//,'') === 
      this.pathname.replace(/^\//,'') && 
      location.hostname === this.hostname) {
      var target = $(this.hash);
      target = target.length ? target : $('[name=' + this.hash.slice(1) +']');
      if (target.length) {
        $('html,body').animate({
          scrollTop: target.offset().top-topoffset
        }, 500);
        return false;
      } //target.length
    } //click function
  }); //smooth scrolling

});

This requires a full version of jQuery in order for this to work. (jquery.slim is insufficient)