JSFiddle - React, Tailwind, and code Playground

HTML

<div class="actAsDiv">
<textarea></textarea><button>
Replace
</button>
</div>

JavaScript

$(function(){
  $('button').on('click', function() {
		var inTextaria = '.actAsDiv > textarea:eq(0)';
    var oldString = $(inTextaria).val();
    var newString = oldString.replace("c", "\n");
		$(inTextaria).val(newString);
  })
})