<html lang="ko">
<head>
<meta charset="UTF-8">
<title>JavaScript String Method</title>
</head>
<body>
<h1>문자열의 대소문자 변환</h1>
<script>
var str = "JavaScript";
document.write(str.toUpperCase() + "<br>"); // JAVASCRIPT
document.write(str.toLowerCase()); // javacript
</script>
</body>
</html>