JSFiddle - React, Tailwind, and code Playground

HTML

<div class="counter"></div>
<button class="stop">stop</button>
<div class="box"></div>

<div class="link">
	<a href="#">リンク1</a>
	<a href="#">リンク2</a>
	<a href="#">リンク3</a>
	<a href="#">リンク4</a>
</div>

CSS

.box{
	margin-bottom: 1500px;
}

.counter{
	width: 100px;
	padding: 5px;
	border: 1px solid #000;
}

JavaScript

$(".box").html("<a href='#'>リンク</a>");

var link = $(".link a");
link.on("click",function(event){
	console.dir(event);
	event.preventDefault();
	console.log($(this).index());
});

//clearInterval
var counter = 0;
var countBox = $(".counter");
function countUp(){
	countBox.html(counter);
	counter++;
}
var timerId = setInterval(countUp,1000);

$(".stop").on("click",function(){
	clearInterval(timerId);
});