CODEWITHSUNDEEP
phpclassconstructor
Arihant
Arihant

Reputation: 4047

How to access member variables of a constructor outside of it in php

I made the following example class

class a{

 function __construct(){
    $a =10;
    $b=9;
    }


}

$z=new a();

I would like to know how can I access $a and $b using the object(or by other means) to perform a single $a + $b addition. I know this can be done using the super global array but I would like to know are there any other methods to do this rather than declaring them global.

I know the code doesn't make much sense but doing it for example purposes

Upvotes: 0

Views: 1685

Answers (4)

ka_lin
ka_lin

Reputation: 9432

You can`t return in the cunstructor even if you do:

    class a{
     public $a;
     public $b;
     function __construct(){
        $this->a =10;
        $this->b=9;
        return 19;
     }
    }
$b = new a();
var_dump($b);

You would get an instance of a, thus you heve the alternatives: make a new method:

<?php
function add()
{
   return $this->a+$this->b;
}
?>

Or generate getter`s (for both) =>

<?php
function getA()
{
   return $this->a;
}
?>

Or declare them public and access them:

$z->a+$z->b;

It depends on you`r app architecture or restrictions you might have or want to impose

Upvotes: 0

Abhik Chakraborty
Abhik Chakraborty

Reputation: 44844

By name constructors are used for any initialization that the object may need before it is used. So if you do the way you are doing 

function __construct(){
    $a =10;
    $b=9;
    }

The variables $a & $b scope are limited to the function __construct().

You may need $a & $b as class variable rather than the function something as

class a{
 public $a;
 public $b;
 function __construct(){
    $this->a =10;
    $this->b=9;
 }
}

$z=new a();
// access a & b as
$z->a ; $z->b

The constructor here will do the initialization job of the variables when you instantiate the object.

Upvotes: 1

Phantom
Phantom

Reputation: 1700

In your example there are two local variables in the function. You should create class fields to access them via object:

class a {

    public $a;
    public $b;

    function __construct() {
        $this->a = 10;
        $this->b = 9;
    }
}

$z = new a();

echo $z->a;

echo $z->b;

Upvotes: 0

Jeff Lambert
Jeff Lambert

Reputation: 24661

Make those variables properties instead:

class a
{
    public $a;
    public $b;

    public function __construct() {
        $this->a = 10;
        $this->b = 9;
    }
}

$z = new a();
echo $z->a;

Better yet though, abstract your operation into a function:

echo $z->addProperties();

// Inside a class
public function addProperties() {
    return $this->a + $this->b;
}

Later on, when you want to add a third property that you need to add to your other two (or even subtract or multiply by), then all you have to do is change your a class, and not any code that actually uses it.

Upvotes: 3

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