JSFiddle - React, Tailwind, and code Playground

HTML

Address:<br>
    <textarea id="myTextarea">
    California Road
    </textarea>
    
    <p>Click the button to select the contents of the text area.</p>
    
    <button id="button">Try it</button>

JavaScript

function go() {
    var e = document.getElementById("myTextarea");
    var startPos = e.selectionStart;
    var endPos = e.selectionEnd;
    var selection = e.value.substring(startPos, endPos)    ;
    alert("It seems to have disappeared, but...\n\"" + selection + "\"");
    e.focus();
}

var btn = document.getElementById("button");
btn.addEventListener(
    "click",
    go,
    false
);