php declare public variable inside function

Question

I want to declare a variable inside a class with an unknown name

class Example {
    function newVar($name, $value) {
        $this->$name = $value;
    }
}

And I want to use it that way

$c = new Example();
$c->newVar('MyVariableName', "This is my Value");
echo($c->MyVariableName);

The Important thing is, that I do not know the name of the variable. So I cannot put a public $MyVariable inside the class.

Is that in anyway possible? and if yes, can i do this with different scopes (private, protected, public) ?

The property is automatically public and you can't define another visibility — Rizier123, Sep 15 '15 at 22:01
possible duplicate of [Can you create instance properties dynamically in PHP?](http://stackoverflow.com/questions/829823/can-you-create-instance-properties-dynamically-in-php) — samrap, Sep 15 '15 at 22:17

score 1 · Answer 1 · answered Sep 15 '15 at 22:12

1

If i am understanding this correctly you can tweak a little bit by using key value array

class Example {
    private $temp;

    function __construct(){
       $this->temp = array();
    }
    function newVar($name, $value) {
        $this->temp[$name] = $value;
    }
    function getVar($name){
        return $this->temp[$name];
    }
}
$c = new Example();
$c->newVar('MyVariableName', "This is my Value");
echo($c->getVar('MyVariableName'));

Instead of using private you can use protected as well.

answered Sep 15 '15 at 22:12

Tom

81
5

This does exactly the same as OP already has, just more code. – Rizier123 Sep 15 '15 at 22:13
but as an object it will be always public but now you can have different permission type on the variable and functions – Tom Sep 15 '15 at 22:17
@voodoo417 I like his method better than mine. – Tom Sep 15 '15 at 22:23

score 1 · Accepted Answer · answered Sep 15 '15 at 22:18

1

U should use magic methods __get and __set (example without checking):

class Example { 
   private $data = [];

   function newVar($name, $value) {
      $this->data[$name] = $value;
   }

   public function __get($property) {
        return $this->data[$property];
   }

   public function __set($property, $value) {
        $this->data[$property] = $value;
   }       
 }


$c = new Example();
$c->newVar('MyVariableName', "This is my Value");
echo($c->MyVariableName); 
// This is my Value

$c->MyVariableName = "New value";
echo($c->MyVariableName);
// New value

See http://php.net/manual/en/language.oop5.magic.php

answered Sep 15 '15 at 22:18

voodoo417

11,861
3
36
40

There is no need for the `newVar()` method, `$c->MyVariableName = "New value";` would suffice for both instantiation and reassignment. – samrap Sep 15 '15 at 22:20
I was just clarifying for the OP. The current example makes it seem like you have to first use the `newVar()` method to instantiate the "property" – samrap Sep 15 '15 at 22:23

score 0 · Answer 3 · answered Sep 15 '15 at 22:04

0

Your looking for magic calling. In PHP you can use the __call() function to do stuff like that. Have a look here: http://www.garfieldtech.com/blog/magical-php-call

Off the top of my head, something like

function __call($vari, $args){
    if(isset($this->$vari){
        $return = $this->$vari;
    }else{
        $return = "Nothing set with that name";
    }
}

This will also work for private, protected and public. Can also use it to call methods as required in a class

answered Sep 15 '15 at 22:04

Doug

547
10
23

the `__call` magic method is used to call dynamic methods, not to set properties. Please have a look at http://php.net/manual/en/language.oop5.overloading.php – samrap Sep 15 '15 at 22:18

php declare public variable inside function

3 Answers3