How to insert html and javascript code with textarea

It is possible to insert/inject html and javascript code using textarea input field into the current page.

consider, you've following textarea:

<div id="output"></div>
<div style="margin: 25px auto; width: 80%; height: auto;">
    <form id="myform" name="myform">
        <textarea id="mytextarea" name="mytextarea" cols="90" rows="20"></textarea>
        <br> <button type="button" id="mybutton">execute</button>
    </form>
</div>

Now, you can add event listener to that above button to extract html and javascript code from the textarea and insert them to the page:

    window.addEventListener('load', function () {
        document.getElementById('mybutton').addEventListener('click', function (e) {
            var mytextarea = document.getElementById('mytextarea');
            var pattern = /<script>([^]+?)<\/script>/mg;
            var matches, txt = mytextarea.value;
            if (txt) {
                while (matches = pattern.exec(txt)) {
                    if (matches[1]) {
                        var tContent = matches[1].replace(/(\n|\r)+/gm, '');
                        var s = document.createElement('script');
                        s.innerText = tContent;
                        document.body.appendChild(s);
                    }
                }
                txt = txt.replace(pattern, '');
            }
            if (txt) {
                document.getElementById('output').innerHTML = txt;
            }
        });
    });