JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="nav">
    <li><a href="#">Top level</a>

        <ul id="items">
            <li><a href="#">Item 01</a>
            </li>
            <li><a href="#" class="selected">Item 02</a>
            </li>
            <li><a href="#">Item 03</a>
            </li>
        </ul>
    </li>
</ul>

CSS

* {margin: 0px; padding: 0px;}
body {background-color: rgb(248,248,248)}
#nav {
    list-style:none;
}
#nav li {
    float:left;
    display:block;
    width:100px;
    position:relative;
    z-index:500;
}
/* this is the parent menu */
 #nav li a {
    display:block;
    padding:15px;
    color:#000;
    border: 1px solid transparent;
}
#nav li a:hover {
    border: 1px solid black;
    
}
 #nav a.open {
    color:#fff;
    background-color: pink;
}
 #nav ul {
    position:absolute;
    display:none;
    padding:0;
    list-style:none;
}
#nav ul li {
    width:100px;
    float:left;
}
 #nav ul a {
    display:block;
    height:15px;
    padding: 15px;
    color:#666;
}
#nav ul a:hover {
    text-decoration:underline;
}
.active{
    background-color: pink;
    
}

JavaScript

var array = [0,1,2,3,4,5]
 
array.splice($.inArray(3,array),1);
debugger;