Perform calculation from a text code

Hi I'm struggling trying to perform a calculation in Laravel 7.

I have a variable like $val = '1000*2'; and I'm looking for a helper function or related to perform it.

eval($val) does not seem to function in a proper way. I just want a function that results in 2000.

TIA

CodePudding user response：

If you only have to deal with multiplication, you could try something like this.

$val = '1000*2';

$parts = explode('*', $val);

$res = array_reduce($parts, function($carry, $item) {
   return $carry * $item; 
}, 1);

echo $res;

CodePudding user response：

I do not advise using eval() to perform calculations with values passed by a user.

If you really want to receive the value at all costs, you can do something like this:

$val = "echo 1000 * 2;";
eval ($val);

$val = eval("return 1000 * 2;");
echo $val;

You can find more information in the documentation. https://www.php.net/manual/pt_BR/function.eval.php

CodePudding user response：

$parser = new StdMathParser();
$AST = $parser->parse($val);

Then I could access it with $AST->getValue().

Thank you!!