PHP String Calculation [closed]

Answer 1

Take a look at the evalMath class on PHPClasses, which can handle quite complex formulae.

Alternatively:

$string = '2 + 2';
list($operand1,$operator,$operand2) = sscanf($string,'%d %[+\-*/] %d');
switch($operator) {
    case '+' :
        $result = $operand1 + $operand2;
        break;
    case '-' :
        $result = $operand1 - $operand2;
        break;
    case '*' :
        $result = $operand1 * $operand2;
        break;
    case '/' :
        $result = $operand1 / $operand2;
        break;
}
echo $result;