<?php
$amal = "+";
$son1 = 10;
$son2 = 5;

switch ($amal) {
    case "+":
        echo $son1 + $son2; // 15
        break;
    case "-":
        echo $son1 - $son2;
        break;
    default:
        echo "Noto‘g‘ri amal!";
}
?>