JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div class="first">first</div>
    <div class="child1">child1</div>

    Paragraph 1
    <br>
    Paragraph 2
    <br/>       
    Paragraph 3

    <div class="child2">child2</div>
    <div class="child3">child3</div>

        Last Content
        <br/>
        Last Content 2
        <br/>
        Last Content 3


    <div class="last">last</div>
</div>

JavaScript

var appendSt = $('.child3').after('code:'),
    content  = $('.parent').clone().children().remove().end().text(),
    reg      = content.replace(/code:([^xyz]+)/, '');
alert(reg);