$str1 = "i want to fly, Fly in the sky ,fly to the Higher!";

$str2 = "i want to fly, Fly in the sky ,fly to the Higher!";

$str3 = "i want to fly, Fly in the sky ,fly to the Higher!";

$str4 = "i want to fly, Fly in the sky ,fly to the Higher!";

echo strtoupper($str1)."<br/>";

echo strtolower($str2)."<br/>";

echo ucfirst($str4)."<br/>";

echo ucwords($str3);