JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="test"></textarea>
<p>Placeholder text</p>
<textarea id="test2" placeholder="example"></textarea>

JavaScript

$(document).ready(function() {
	//On init:
	var initPlaceholderTxt = $("p").text();
  
  //Execution:
  
  //Using this, placeholder will not display correct information, 
  //lacking a previous clicked character:
  $("#test").on("keydown", function( event ) {
  	var value = $( this ).val();
  	$("p").text(value);
    $("#test2").attr("placeholder",value)
  });
  
  /*
  //Core feature:
	$("#test").keyup(function() {
  	var value = $( this ).val();
    if(value != null && value != "") {
  		$("p").text(value);
    }
    else {
    	$("p").text(initPlaceholderTxt);
    }
  });
  
  //Make characters appear more dynamically or faster:
  $("#test").keydown(function() {
  	var value = $( this ).val();
  	$("p").text(value);
  });
  */
});