var text = "";
var i;
for (i = 0; i < 5; i++) {
text += "The number is " + i + "<br>";
}
document.getElementById("demo").innerHTML = text;
<!DOCTYPE html>
<html lang="ko">
<head></head>
<body>
<h1>JavaScript for</h1>
<p id="demo"></p>
</body>
</html>