Sort function doesnt work

chrisdee

Im am trying to sort the output from a textfile by description with the php script below, but it doesnt work. Any ideas ?

<? 
echo "<table border=1 cellpadding=4 cellspacing=0>"; 
echo "<tr> 
    <td bgcolor=lightgrey><a href=names.php?sort=l>Lastname</td> 
    <td bgcolor=lightgrey><a href=names.php?sort=f>Firstname</a></td> 
</tr>"; 

$array = file("names.txt"); 
usort($array,my_sort); 

foreach ($array as $line) { 
  $part=split(";",$line); 
  echo "<tr> 
    <td>$part[0]</td> 
    <td>$part[1]</td> 
    </tr>"; 
} 

echo "</table>"; 
echo "</td></tr></table>"; 

function my_sort($a,$b) { 
global $sort; 
$part_a=preg_split("/;/",$a); 
$part_b=preg_split("/;/",$b); 

if($sort == "l") 
  return cmp($part_a[0],$part_b[0]); 
elseif($sort == "f") 
  return cmp($part_a[1],$part_b[1]); 
else return 0; 
} 

function cmp($a,$b) { 
$a=strtoupper($a); 
$b=strtoupper($b); 

if($a>$b) 
  return 1; 
elseif($a==$b) 
  return 0; 
else return -1; 
} 
?>

Installer

The callback function name should be passed as a string ('mysort'). And where do you define "$sort"?

Weedpacket

http://www.phpbuilder.com/board/showthread.php?s=&threadid=10297745

Oh, and Question One from here.

chrisdee

Im not shure what you mean. Could anybody show me example.
Thank you.

mijokijo

<? 
echo "<table border=1 cellpadding=4 cellspacing=0>"; 
echo "<tr> 
    <td bgcolor=lightgrey><a href=names.php?sort=l>Lastname</td> 
    <td bgcolor=lightgrey><a href=names.php?sort=f>Firstname</a></td> 
</tr>"; 

$array = file("names.txt"); 
usort($array,my_sort); // This is a callback function. 

foreach ($array as $line) { 
  $part=split(";",$line); 
  echo "<tr> 
    <td>$part[0]</td> 
    <td>$part[1]</td> 
    </tr>"; 
}

This should be...

<? 
echo "<table border=1 cellpadding=4 cellspacing=0>"; 
echo "<tr> 
    <td bgcolor=lightgrey><a href=names.php?sort=l>Lastname</td> 
    <td bgcolor=lightgrey><a href=names.php?sort=f>Firstname</a></td> 
</tr>"; 

$array = file("names.txt"); 
usort($array,'my_sort'); // <-- Notice the single-quotes 

foreach ($array as $line) { 
  $part=split(";",$line); 
  echo "<tr> 
    <td>$part[0]</td> 
    <td>$part[1]</td> 
    </tr>"; 
}

Check out the below link to understand callback functions a bit more.
http://us2.php.net/language.pseudo-types

chrisdee

Thank you for suggestion. I tried it, but it still doesnt work.
What can be wrong else ?

mijokijo

Could you give us the error you're getting? I think that is what Weedpacket was hinting at.