Addition by ZERO - PHP - php

Question

Could somebody please tell me why $total_value evaluates to ZERO when either $bawtry_value or $chain_value are non-zero values?
PHP
$bawtry_value = utf8_encode(money('%n', $bawtry * $price));
echo "Bawtry Value";
echo '<br />';
echo $bawtry_value;
echo '<br />';
$chain_value = utf8_encode(money('%n', $chain * $price));
echo "Chain value";
echo '<br />';
echo $chain_value;
echo '<br />';
$total_value = utf8_encode(money('%n', $bawtry_value + $chain_value));
echo "Total value";
echo '<br />';
echo $total_value;
echo '<br />';
Example Output
Result Bawtry 0
Result Chain 2
Total Pairs 2
Bawtry Value
£0.00
Chain value
£39.90
Total value
£0.00
Is there a problem with PHP adding two figures together when one is ZERO?
Any help would be great. Thanks

Answer 1

It seems you should change this line:
$total_value = utf8_encode(money('%n', $bawtry_value + $chain_value));
into
$total_value = utf8_encode(money('%n', $bawtry * $price + $chain * $price));
or even
$total_value = utf8_encode(money('%n', $price * ($bawtry + $chain)));
Now in calculating $total_value you have currency symbol at the beginning of $bawtry_value and $chaing_value and if you add them, they are converted to 0.
You can see this if you try to display:
echo '£0.00' + '£39.90';
first character of those strings is £ is converted to 0.
However if you try to do something like that
echo '2£0.00' + '39.90£';
result will be 41.90 because strings are converted to int until the first character that makes the string cannot be converted to int.