JSFiddle - React, Tailwind, and code Playground

HTML

<html>
    <body>
        <h4 class="b" id="b1">B1</h4>
        <h4 class="b" id="b2">B2</h4>
        <h4 class="b" id="b3">B3</h4>
        <hr/>
        <section id="section1" class="hideme">
            section1
        </section>
        <section id="section2" class="hideme">
            section2
        </section>
        <section id="section3" class="hideme">
            section3
        </section>
    </body>
</html>

CSS

.hideme {
    background-color: lime;
}

JavaScript

$(document).ready(function() {
    $("section.hideme").hide();
    $("h4.b").click(function() {
        var id = $(this).attr("id");
        var sectionId = id.replace("b", "section");
        $("section.hideme").hide();
        $("section#" + sectionId).fadeIn("slow");
    });
});