访问PHP foreach循环外的变量

Question

In some code I'm working on I have noticed that several variables are being accessed from outside of foreach loops.

This is seen in codeigniter view files of this particular app.

For example, a view file:

<?php
foreach ($items as $row):
endforeach;

// HTML / PHP code...

 <td>
     <?php echo form_checkbox('option_1','1', FALSE); ?>
     <?php echo form_hidden('weight_unit', $row->weight_unit); ?>
 </td>
// etc...

This works (ie, no errors) but I wonder if this would be considered a bad practice and if so, why? (scope, etc)

Does anyone have an opinion on this and should variables only be called inside their corresponding loops?

Another issue I've noticed is if a variable is required in several parts of a view file: should I refactor to have multiple loops or should there be a single foreach / endforeach and the begin / end of the file.

Any suggestions are much appreciated. Thanks.

Answer 1

$row will be the last item in the array, or unset, when it reaches your other code.

Is that want you want? If so, then it's not bad practice, per se. But you should at least document that the behavior is intended, because it's not intuitive.

Better practice is something like:

foreach ($foo as $bar) 
{
  // do something
}
$last_bar = isset($bar) ? $bar : null;

There it's obvious that you mean to do something with $last_bar.

Another issue I've noticed is if a variable is required in several parts of a view file

If you must iterate over your loop in different places in your view, then that's okay.

But if you just need a certain piece of information deep inside some array, then you should stick it into an easily accessible variable and use that instead.