Блондинка,
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style>
div {
padding: 10px;
margin: 0 0 5px 0;
border: 1px solid #999;
}
#text {
border: 1px solid #a9a9a9;
background-color: hsl(120, 100%, 98%);
color: hsl(120, 100%, 20%);
padding: 5px;
font: 18px serif;
outline: none;
}
</style>
</head>
<body>
<script>
var plural = function (b) {
return function (a) {
return b[1 == a % 10 && 11 != a % 100 ? 0 : 2 <= a % 10 && 4 >= a % 10 && (10 > a % 100 || 20 <= a % 100) ? 1 : 2]
}
};
var d = plural(['символ','символа','символов'])
function schet()
{
var text = document.getElementById('text');
var content = text.value;
var dlina = content.length;
var divx = document.getElementById('otvet');
var text = `${dlina} ${d(dlina)}`
divx.textContent = text;
}
</script>
<div>
<textarea oninput = "schet()" id="text" cols="30" rows="5" wrap="soft"></textarea>
</div>
<div> в поле ввода введено <span id="otvet">0 символов</span></div>
</body>
</html>