php sum with add symbol as variable

Question

I have this variable

$option_value['price'] = 2
$option_value['price_prefix'] = +
$this->data['price2'] = 3

I have tried to make sum from it like this

$price = $option_value['price'].''.$option_value['price_prefix'].''.$this->data['price2'];
echo $price

but the result is 2. What I want is 5.

Prease help

See https://stackoverflow.com/questions/7293087/how-do-i-do-the-calculation-with-a-variable-in-php — MPAvance, Feb 28 '18 at 15:15
If your set of variables was anywhere near correct (missing `;`'s, + should be in quotes) then you'd get `2+3` as the output. — Nigel Ren, Feb 28 '18 at 15:17

score 0 · Accepted Answer · answered Feb 28 '18 at 16:19

Under the assumption that the prefix is always either + or -, something like this should do the trick (I've changed the variable names for the sake of readability):

$price = 2;
$prefix = "+";
$price2 = 3;

$total = $price + ($prefix.$price2);

This concatenates the prefix and the second price to "+3" which will then be cast implicitly to an integer for the addition with the first price. The parentheses make sure that the concatenation is done before the addition. Otherwise the addition would precede and that would lead to concatenation rather than addition.

score 0 · Answer 2 · edited Feb 28 '18 at 20:25

0

You can do this like this:

<?php

$option_value['price'] = 2;
$option_value['price_prefix'] = '+';
$option_value['price2'] = 3;

$price = $option_value['price']+$option_value['price_prefix']+$option_value['price2'];
echo $price; 

?>

edited Feb 28 '18 at 20:25

Xenolion

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answered Feb 28 '18 at 16:42

Mohit Kumar

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it don't work. When I change $option_value['price_prefix'] = '-'; the result still the same – Faiz Feb 28 '18 at 22:26

php sum with add symbol as variable

2 Answers2