StrToLower() & StrToUpper() String Functions

phpThere are numerous string functions in PHP.  Two of them are strtolower() means string to lower case and strtoupper() string to upper case.  You can use these 2 string functions in case you want to change the case of a string completely.  Example of these 2 functions is given below.

$hello = "Hello World!";

//Original string.
echo $hello."<br />";

//In Lower Case.
echo strtolower($hello)."<br />";

//In Upper Case.
echo strtoupper($hello)."<br />";