I'm building a simple weight log, where there'a table that display the user's progress. I'm using Codeigniter.
<?php foreach($logs as $log) : ?>
<tr>
<td><?php echo $log->date ;?></td>
<td><?php echo $log->weight ;?> kg.</td>
<td><!-- variation between this record and previous record. weigth[a] - weight[b] --></td>
<td></td>
<td><?php echo anchor('logs/edit/'.$log->id, 'Editar'); ?> <?php echo anchor('logs/delete/'.$log->id, 'Delete'); ?></td>
</tr>
<?php endforeach ;?>
I'm trying to calculate the variation between the first row and the second row, so as to get the weight loss or gain between logs. I was wondering how to access the loop's previous record so as to substract it from the current record's weight.
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DATE | WEIGHT | VARIATION
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Nov 20 | 70 kg | -1 kg << LAST LOGGED WEIGHT, FIRST IN ARRAY
.......................................
Nov 15 | 71 kg | -
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