Using mb_strtoupper() to Convert Strings to Uppercase in PHP

The mb_strtoupper() function in PHP converts all alphabetic characters in a string to uppercase, optionally using a specified character encoding.

Signature: string mb_strtoupper(string $str [, string $encoding = mb_internal_encoding()])

Description: The function returns the input string with all letters transformed to uppercase according to the given or internal encoding.

Parameters:

str : The string to be converted to uppercase.

encoding (optional): The character encoding to use; if omitted, the internal encoding is applied.

Return value: The uppercase version of $str .

Example 1 (English text):

<?php
$str = "Mary Had A Little Lamb and She LOVED It So";
$str = mb_strtoupper($str);
echo $str;
// Prints MARY HAD A LITTLE LAMB AND SHE LOVED IT SO
?>

Example 2 (Unicode text):

<?php
$str = "Τ?χιστη αλ?πηξ βαφ?? ψημ?νη γη, δρασκελ?ζει υπ?ρ νωθρο? κυν??";
$str = mb_strtoupper($str, 'UTF-8');
echo $str;
// Prints Τ?ΧΙΣΤΗ ΑΛ?ΠΗΞ ΒΑΦ?Σ ΨΗΜ?ΝΗ ΓΗ, ΔΡΑΣΚΕΛ?ΖΕΙ ΥΠ?Ρ ΝΩΘΡΟ? ΚΥΝ?Σ
?>