JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id = "a"></textarea>
<button id = "print">Print</button>
<p id = "b"></p>

JavaScript

function nl2br (str) {
    var regex = /([^>\r\n]?)(\r\n|\n\r|\r|\n)/g;
    return (str + '').replace(regex, '$1<br />$2');
}

var print = document.getElementById("print"),
    a = document.getElementById("a"),
    b = document.getElementById("b");

print.addEventListener("click", function(){
    b.innerHTML = nl2br(a.value);
});