PHP中余数、取余的妙用

<?php $ary=array("name","egineer","sonny","tonny","pingk","apple","phone","clone","pink","colle");foreach($ary as $key=>$value){$key=$key+1;if($key%2==1){echo '<li>';}  ?> <span><?php echo $key.":". $value;?></span> <?php if($key%2==0){echo '</li>';}}; ?>

 <?php $ary=array("name","egineer","sonny","tonny","pingk","apple","phone","clone","pink","colle");foreach($ary as $key=>$value){$key=$key;if($key%3==0){echo '<li>';}  ?> <span class="<?php echo($key%3); ?>span"><?php echo $key.":". $value;?></span> <?php if($key%3==2){echo '</li>';}}; ?>