Question

I have string like this: $string = "a + b + c";. Now I would like to calculate the string as sum.

For example:

$a = 10;
$b = 10;
$c = 10;
$string = "a + b + c";

echo "Result is ".$string;
output-> Result is 30

$string = "a + b * c";

echo "Result is ".$string;
output-> Result is 110

Thanks in advance

Answer 1

The variables in your string are missing the dollar signs. I wrote and tested a script for you that adds these signs to the variables and then parses the string as PHP code using the function eval().

$a = 10;
$b = 10;
$c = 10;
$string = "a + b + c";

$result = eval('return ' . preg_replace('/([a-zA-Z0-9])+/', '\$$1', $string) . ';');
echo $result;

This will output 30.