Setting a variable to an operator then executing it

问题

I'm new to PHP in general. I was messing with this code until I wanted to execute the function in one set instead of having to set and add, sub, div, mult function. How do I go about setting the variable operator with the two num sets?

Example pseudo code:

<?php
$Num1 = 10;
$Num2 = 5;
$operation = /;
$Sum = $Num1 $operation $Num2;
return $Sum;

Or something like:

<?php
// creating Class "Math"
class math {
    //Executing the function
    function exec($info = array()) {
      return $info['num1'] $info['operation'] $info['num2'];
    }
}

// Set info
$info = array(
    'num1' => 10,
    'num2' => 5,
    'operation' => '/'
);

//execute the OOP
$math = new math;
echo $math->exec($info);

回答1:

What you are asking for is referred to as the Strategy Pattern.

One way to do this is to define your functions

$multiply = function($operand0, $operand1) {
    return $operand0*$operand1;
};

$add = function($operand0, $operand1) {
    return $operand0+$operand1;
};

Then using your sample code:

class math {
    //Executing the function
    function exec($info = array()) {
      return $info['operation']($info['num1'], $info['num2']);
    }
}

// Set info
$info = array(
    'num1' => 10,
    'num2' => 5,
    'operation' => $add
);

//execute the OOP
$math = new math;
echo $math->exec($info); //will print 15

来源：https://stackoverflow.com/questions/24102923/setting-a-variable-to-an-operator-then-executing-it