Php – Get and set (private) property in PHP as in C# without using getter setter magic method overloading

gettergetter-setterPHPpropertiessetter

Summary

Code sample:

Class People {
    // private property.
    private $name;

    // other methods not shown for simplicity.
}

Straight forward. Let me assume that $name is a PRIVATE class member (or property, variable, field, call it as you wish). Is there any way to do these in PHP:

$someone = new People();
$someone->name = $value;
$somevar = $someone->name;

WITHOUT using __get($name) and __set($name, $value).

Background

I needed to check the assigned $value, therefore I simply need a getter setter like this:

getName();
setName($value);

And NOT necessarily a getter setter magic method overloading like this:

__get($value); 
__set($value, $name);

That said, I simply need a getter setter. But that's NOT what I want. It just doesn't feel like object oriented, for people from static typed language such as C++ or C# might feel the same way as I do.

Is there any way to get and set a private property in PHP as in C# without using getter setter magic method overloading?

Update

Why Not Magic Method?

There are rumors floating around the web that magic method is 10x slower then explicit getter setter method, I haven't tested it yet, but it's a good thing to keep in mind. (Figured out that it's not that slow, just 2x slower, see the benchmark result below)
I have to stuff everything in one huge method if I use magic method rather then split them into different function for each property as in explicit getter setter. (This requirement might have been answered by ircmaxell)

Performance Overhead Benchmarking

I'm curious about performance overhead between using magic method and explicit getter setter, therefore I created my own benchmark for both method and hopefully it can be useful to anyone read this.

With magic method and method_exist:

(click here to see the code)

Getter costs 0.0004730224609375 second.
Setter costs 0.00014305114746094 second.

With explicit getter setter:

(click here to see the code)

Getter costs 0.00020718574523926 second.
Setter costs 7.9870223999023E-5 second (that's 0.00007xxx).

That said, both setter and getter with magic method and method exists justs costs 2x than the explicit getter setter. I think it's still acceptable to use it for a small and medium scale system.

Best Answer

Nope.

However what's wrong with using __get and __set that act as dynamic proxies to getName() and setName($val) respectively? Something like:

public function __get($name) { 
    if (method_exists($this, 'get'.$name)) { 
        $method = 'get' . $name; 
        return $this->$method(); 
    } else { 
        throw new OutOfBoundsException('Member is not gettable');
    }
}

That way you're not stuffing everything into one monster method, but you still can use $foo->bar = 'baz'; syntax with private/protected member variables...

Related Solutions

Php – How to get the current date and time in PHP

The time would go by your server time. An easy workaround for this is to manually set the timezone by using date_default_timezone_set before the date() or time() functions are called to.

I'm in Melbourne, Australia so I have something like this:

date_default_timezone_set('Australia/Melbourne');

Or another example is LA - US:

date_default_timezone_set('America/Los_Angeles');

You can also see what timezone the server is currently in via:

date_default_timezone_get();

So something like:

$timezone = date_default_timezone_get();
echo "The current server timezone is: " . $timezone;

So the short answer for your question would be:

// Change the line below to your timezone!
date_default_timezone_set('Australia/Melbourne');
$date = date('m/d/Y h:i:s a', time());

Then all the times would be to the timezone you just set :)

PHP 5.3 Magic Method __invoke

The use of __invoke makes sense when you need a callable that has to to maintain some internal state. Lets say you want to sort the following array:

$arr = [
    ['key' => 3, 'value' => 10, 'weight' => 100], 
    ['key' => 5, 'value' => 10, 'weight' => 50], 
    ['key' => 2, 'value' => 3, 'weight' => 0], 
    ['key' => 4, 'value' => 2, 'weight' => 400], 
    ['key' => 1, 'value' => 9, 'weight' => 150]
];

The usort function allows you to sort an array using some function, very simple. However in this case we want to sort the array using its inner arrays 'value' key, what could be done this way:

$comparisonFn = function($a, $b) {
    return $a['value'] < $b['value'] ? -1 : ($a['value'] > $b['value'] ? 1 : 0);
};
usort($arr, $comparisonFn);

// ['key' => 'w', 'value' => 2] will be the first element, 
// ['key' => 'w', 'value' => 3] will be the second, etc

Now maybe you need to sort the array again, but this time using 'key' as the target key, it would be necessary to rewrite the function:

usort($arr, function($a, $b) {
    return $a['key'] < $b['key'] ? -1 : ($a['key'] > $b['key'] ? 1 : 0);
});

As you can see the logic of the function is identical to the previous one, however we can't reuse the previous due to the necessity of sorting with a different key. This problem can be addressed with a class that encapsulates the logic of comparison in the __invoke method and that define the key to be used in its constructor:

class Comparator {
    protected $key;

    public function __construct($key) {
            $this->key = $key;
    }

    public function __invoke($a, $b) {
            return $a[$this->key] < $b[$this->key] ? 
               -1 : ($a[$this->key] > $b[$this->key] ? 1 : 0);
    }
}

A Class object that implements __invoke it's a "callable", it can be used in any context that a function could be, so now we can simply instantiate Comparator objects and pass them to the usort function:

usort($arr, new Comparator('key')); // sort by 'key'

usort($arr, new Comparator('value')); // sort by 'value'

usort($arr, new Comparator('weight')); // sort by 'weight'

The following paragraphs reflect my subjective opinion, so if you want you can stop reading the answer now ;): Although the previous example showed a very interesting use of __invoke, such cases are rare and I would avoid its use since it can be done in really confusing ways and generally there are simpler implementation alternatives. An example of an alternative in the same sorting problem would be the use of a function that returns a comparison function:

function getComparisonByKeyFn($key) {
    return function($a, $b) use ($key) {
            return $a[$key] < $b[$key] ? -1 : ($a[$key] > $b[$key] ? 1 : 0);
    };
}
usort($arr, getComparisonByKeyFn('weight'));
usort($arr, getComparisonByKeyFn('key'));
usort($arr, getComparisonByKeyFn('value'));

Although this example requires a little more intimacy with lambdas | closures | anonymous functions it's much more concise since it doesn't create a whole class structure just to store an outer value.