JSFiddle - React, Tailwind, and code Playground

by the94air

HTML

<ul>
    <li>Item 1</li>
    <li>Item 2</li>
    <li>Item 3</li>
</ul>

CSS

li.selected {background:yellow}

JavaScript

var li = $('li');
var liSelected;
$(window).keydown(function(e){
    if(e.which === 40){
        if(liSelected){
            liSelected.removeClass('selected');
            next = liSelected.next();
            if(next.length > 0){
                liSelected = next.addClass('selected');
            }else{
                liSelected = li.eq(0).addClass('selected');
            }
        }else{
            liSelected = li.eq(0).addClass('selected');
        }
    }else if(e.which === 38){
        if(liSelected){
            liSelected.removeClass('selected');
            next = liSelected.prev();
            if(next.length > 0){
                liSelected = next.addClass('selected');
            }else{
                liSelected = li.last().addClass('selected');
            }
        }else{
            liSelected = li.last().addClass('selected');
        }
    }
});