Math.max()
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<script>
var arr = [1,2,3];
console.log(Math.max(12,1,2));
console.log(Math.max(...arr));
</script>
</body>
</html>