JSFiddle - React, Tailwind, and code Playground

HTML

<div id="block-id-45"></div>
<div id="block-id-5"></div>
<div id="block-of-cheese"></div>
<div id="block-id-12"></div>
<div id="block-id-43"></div>

JavaScript

$(function() {
    $("div[id^='block-id-']").each(function() {
        // You could push this data to an array too
        $("body").append( "Id number: " + $(this).attr("id").match(/[\d]+$/) + "<br/>" );
    });
});