JSFiddle - React, Tailwind, and code Playground
HTML
<div>
<div class="tel">
<a href="#">12345678Something</a>
</div>
<div class="tel">
<a href="#">12345678Another</a>
</div>
</div>
JavaScript
var data = $("div");
var phoneArray = $(data).find(".tel a").map(function (i, el) {
return $(el).text().substring(8);
}).get();
console.log(phoneArray);