<?php 

$i = 0;
foreach($degisken as $deg): 
 $i++;
 
// .......

 if ($i==count($degisken)) echo "son";
endforeach;

 ?>

$soneleman = end($dizi);


foreach($degisken as $deg): ?>

<?php echo $deg['sutun'];?>
if($soneleman==$deg['sutun']){
Echo 'buraya birsey yaz' ;
}
<?php endforeach ?>