How would I call a method from a class with a variable?

Question

Given this class:

class Tacobell{

    public function order_taco(){
        echo "3 Tacos, thank you.";
    }

    public function order_burrito(){
        echo "Cheesy bean and rice, please";
    }

}

$lunch = new Tacobell;
$lunch->order_burrito();
$lunch->order_taco();

How would I do something like this?

$myOrder = 'burrito';
$lunch->order_.$myOrder;

Obviously that code is bunk--but shows what I'm attempting to do better than trying to explain it away.

And maybe I'm going about this all wrong. I thought about a method with a switch statement, pass in burrito or taco, then call the right method from there. But then I have to know the end from the beginning, and I may potentially have lots of methods and I'd rather not have to update the switch statement everytime.

Thanks!

This could be done using objects, you can have classes for each item, each can conform to the same interface, then have a single order() method that will take a OrderItem object which could either be a BurritoOrderItem or a TacoOrderItem. I always cringe when Reflection is needed or when you have variable method calls, it just isn't clean to me. — Kekoa, Jun 01 '09 at 21:33

score 5 · Accepted Answer · answered Jun 01 '09 at 21:50

5

How about something like this?

class Tacobell {
    public function order_burrito() {
         echo "Bladibla.\n";
    }

    public function order($item) {
        if (method_exists($this, "order_$item")) {
            $this->{'order_' . $item}();
        } else {
            echo "Go away, we don't serve $item here.\n";
        }
    }
}

You would call it using $lunch->order('burrito');, which looks much cleaner to me. It puts all the uglyness in the method Tacobell::order.

answered Jun 01 '09 at 21:50

rodion

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All the answers so far have been what I needed, but this what I was looking for. Thanks all. I'm still not sure this is how I want to do it though, but for now it gets the most reuse out of my code. – Ryan Florence Jun 01 '09 at 23:30

score 3 · Answer 2 · answered Jun 01 '09 at 21:29

3

$lunch->{'order_' . $myOrder}();

I do agree the design is a little iffy, but that's how to do it at least.

answered Jun 01 '09 at 21:29

Paolo Bergantino

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score 2 · Answer 3 · answered Jun 01 '09 at 21:34

2

I think call_user_func is what you're looking for:

http://us3.php.net/call_user_func

You can pass it the string you suggested. See example #3 for calling a method of a class.

answered Jun 01 '09 at 21:34

kris

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score 0 · Answer 4 · answered Jun 02 '09 at 00:01

0

simple enough

$order = 'order_burrito';
$lunch->$order();

answered Jun 02 '09 at 00:01

Ozzy

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How would I call a method from a class with a variable?

4 Answers4

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