JSFiddle - React, Tailwind, and code Playground

by LuckyCat

HTML

<pre id="demo"></pre>

JavaScript

function writeTextByJS(id, text, speed){

	var ele = document.getElementById(id),
	    txt = text.join("").split("");

	var interval = setInterval(function(){

		if(!txt[0]){

			return clearInterval(interval);
		};

		ele.innerHTML += txt.shift();
	}, speed != undefined ? speed : 100);

	return false;
}


writeTextByJS(
	"demo",
	[
		"Первая строка\n",
		"Вторая строка\n"
	]
);