JSFiddle - React, Tailwind, and code Playground

HTML

<textarea class="myClass" id="FurnishingDetails" name="FurnishingDetails" id="FurnishingDetails"></textarea>

CSS

textarea[name='FurnishingDetails']{
 height:2em;  
}

JavaScript

$('#FurnishingDetails').text('hello\nhello1\nhello2\nhello3\nhello4\nhello5');
String.prototype.lines = function() { return $('#FurnishingDetails').text().split(/\r*\n/); }
String.prototype.lineCount = function() { return $('#FurnishingDetails').text().lines().length; }
alert($('#FurnishingDetails').text().lineCount());
$('#FurnishingDetails').css('height', ($('#FurnishingDetails').text().lineCount() + 1) + 'em');