PHP, Structures and Functions, STRINGS

If $str1 is less than $str2 this function retuns an integer less than ZERO.

If $str1 is equal to $str2 this function returns ZERO.

If $str1 is greater than $str2 this function returns an an integer greater than ZERO.

This function implements a comparison algorithm that orders alphanumeric STRINGS in the way a human being would, this is described as a natural ordering.

This functiom is binary-safe

This function is CASE INSENSITIVE

Natural Order String Comparison


<?php

int strnatcasecmp ( str $str1 , str $str2 )


where,

$str1 = The first STRING to compare 

$str2 = The second STRING to compare

?>

$str1

The first STRING to be compared.

$str2

The second STRING to be compared.

EXERCISE


<?php

$strnccmp01a = "Better late than never!";

$strnccmp01b = "BETTER LATE THAN NEVER!";

$lenght01 = 6; 
// 6 initial characters

$intnccmp01ab = strnatcasecmp ($strnccmp01a, 
                                                    $strnccmp01b);

if ($intnccmp01ab > 0)
{
echo substr($strnccmp01a, 0, $lenght01)  . 
'<br>is GREATER than<br>' . 
substr($strnccmp01b, 0, $lenght01);
}
elseif ($intnccmp01ab < 0)
{
echo substr($strnccmp01a, 0, $lenght01) . 
'<br>is LESS than<br>' . 
substr($strnccmp01b, 0, $lenght01);
}
else
{
echo substr($strnccmp01a, 0, $lenght01) . 
'<br>is EQUAL to<br>' . 
substr($strnccmp01b, 0, $lenght01);
}

?>

EXERCISE


<?php  

$tst02 = glob('' . "*{.JPG,.jpg,.txt,.TXT,
                             .mp3,.MP3,
                             .wav,.WAV,
                             .m4a,.M4A}", GLOB_BRACE); 

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -   
   This code retrieves all files in the  
   specified directory, if they are: 
   .JPG,.jpg,.txt,.TXT,.mp3, .MP3, .wav, .WAV, .m4a, .M4A  
    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ 

usort($tst02, "strnatcasecmp");

foreach($tst02 as $ts02)
{
echo basename($ts02) . '<br>';
}    

?>

EXERCISE


<?php

function str_dump($one, $two) {
    echo "<br>$one<br>and<br>$two<br><br>Returned value: ";
    var_dump(strnatcasecmp($one, $two));
    echo '<br>- - - - - - -<br>';
}

echo "Testing strnatcasecmp() : basic functionality.<br>";

// Calling strnatcasecmp() with all possible arguments
echo '- - - - - - -<br>';
str_dump('A', 'a');
str_dump('a10', 'A20');
str_dump('A1b', 'a');
str_dump('x2-y7', 'x8-y8');
str_dump('1.010', '1.001');
str_dump(' ab', ' aB');
str_dump('acc ', 'acc');
str_dump(11.5, 10.5);
str_dump(10.5, 10.5E1);
str_dump('Rfc822.txt', 'rfc2086.txt');
str_dump('Rfc822.txt', 'rfc822.TXT');
str_dump('pIc 6', 'pic   7');
str_dump(0xFFF, 0Xfff);

?>

EXERCISE


<?php

/* Preparation */
class a
{
    function __toString()
    {
        return "Hello WORLD";
    }
}

class b
{
    function __toString()
    {
        return "HELLO world";
    }
}

$a = new a();
$b = new b();

function str_dump($a, $b) {
    echo "<br>$a<br>and<br>$b<br>";
    var_dump(strnatcasecmp($a, $b));
    echo '<br><br>';
}

echo "Testing strnatcasecmp() : variation:<br>";

str_dump('0', false);
str_dump('fooBar', '');
str_dump('', -1);
str_dump("Hello\0world", "Helloworld");
str_dump("\x0", "\0");
str_dump($a, $b);

?>