JSFiddle - React, Tailwind, and code Playground

HTML

<a class="menu active">link 1</a>

<a class="menu">link 2</a>

<a class="menu">link 3</a>

CSS

.menu {
    color:blue;
    text-decoration: underline;
    cursor:pointer;
}
.menu.active {
    color:red;
}

JavaScript

[].forEach.call(document.querySelectorAll(".menu"), function (item) {
    item.addEventListener("click", function (e) {
        if (this.classList.contains("active")) return;
        var active = document.querySelector(".menu.active");
        active && active.classList.remove("active");
        this.classList.add("active");
    });
});