convert to capital letters php code example

Example 1: php uppercase

//string to all uppercase
$string = "String with Mixed use of Uppercase and Lowercase";
//php string to uppercase
$string = strtoupper($string);
// = "STRING WITH MIXED USE OF UPPERCASE AND LOWERCASE"

Example 2: php code to convert to small letter

$str = strtolower($str);

Example 3: php string to uppercase

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

Example 4: php open file capital letters or not

$result = current(preg_grep("/".preg_quote($filename)."/i", glob("$path/*")));