<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
function una() {
var lanEle = document.getElementById('un');
var a = lanEle.value;
console.log(a);
var inn = document.getElementById('aa').innerHTML;
document.getElementById('aa').innerHTML = inn + a + '<br>';
lanEle.value = '';
lanEle.focus();
}
</script>
</head>
<body>
사용 가능 언어
<input type="text" id="un">
<button onclick="una()">추가</button>
<hr>
사용 가능 언어 리스트 <br>
<div id="aa"></div>
</body>
</html>