Difference between array type and object type in PHP

Question

As I know, an array in php can designed by key and value. e.q.

$person = array(
 'name'=>'JOSH',
 'age'=>18
);

It likes an object but just defined by another way. e.q.

class info{
  $name;
  $age;
}
$person = new info();
$person->name = 'JOSH';
$person->age = 18;

I always use array in PHP, but some of my co-workers they say the object type is better than array type.

But I don't understand what different between array type and object type.

Can someone tell me what different between this two types if I just want to declare variable in PHP ?

Objects aren't simply a collection of data like an array, but a collection of behaviours as well.... but to detail all the differences is too extensive to answer on SO — Mark Baker, Mar 06 '15 at 18:54
Please see [When should I use stdClass and when should I use an array in php oo code?](http://stackoverflow.com/questions/3193765/when-should-i-use-stdclass-and-when-should-i-use-an-array-in-php-oo-code) — Rene Korss, Mar 06 '15 at 18:55
@JohnConde after visiting the duplicate page, I feel that the other page is VERY narrow about what aspect is being compared. This page is broadly asking what the differences are. For this reason, I feel the duplicate justification should be amended -- I won't suggest that this page should be Reopened as it is also Too Broad as MarkBaker has commented. — mickmackusa, Jun 27 '19 at 06:59

score 1 · Answer 1 · edited Feb 25 '19 at 09:45

There are a lot of differences, but the object is more powerfull.

Is in a way to avoid rewrite code, and clean the code.

Think you want to do some operations to numbers in an array:

To keep it simple, I suppose you already get the values from array or object.

            <?
            $item = array(
             'name'=>'carrot',
             'price'=>0.20,
             'stock' => 15
            );
            ?>

For example, in an shop context, you want to get the price befor buy, and update the stock.

            <?
            function getprice($item){
                return $item['price'];
            }

            function substock($item,$units){
                $item['stock'] = $item['stock'] - $units;
            }

            echo getprice($item);
            echo "<br/>";
            echo substock($item,"3");
            ?>

It will output something like: 0.20 12

That can be a way, but what can we do with the objects:

            <?
            class items{
                var $name , $price, $stock;

                function __construct($in_name, $in_price, $in_stock){
                    if (!empty($in_name)){$this->name = $in_name;}
                    if (!empty($in_price)){$this->price = $in_price;}
                    if (!empty($in_stock)){$this->stock = $in_stock;}       
                } 

                function getprice(){
                    return $this->price;
                }

                function substock($units){
                    $newstock = $this->stock - $units;
                    $this->stock = $newstock;
                    return $newstock;
                }
            }


            $item = new items("carrot","0.20","15");
            echo $item->getprice();
            echo "<br/>";
            echo $item->substock("3");
            ?>

It will output something like: 0.20 12

Till this point is not a prety much difference, is'n it?

But imagine you want to create a bigger thing. Just play around with it.

Now I want to load an item just with the name of the carrot.

Then changing the method construct to be able to create an objet with different inputs:

                var $name , $price, $stock;

                function __construct($in_name, $in_price=NULL, $in_stock=NULL){
                    $args = func_num_args();
                    if ($args == 1){
                        $this->name = $in_name;
                        $this->fromdb($in_name);
                    }else{
                        if (!empty($in_name)){$this->name = $in_name;}
                        if (!empty($in_price)){$this->price = $in_price;}
                        if (!empty($in_stock)){$this->stock = $in_stock;}       
                    }
                } 

                function fromdb($name){
                    $sql = "SELECT * FROM items WHERE name = '" . $name . "'";
                    //... here we bring from database the item and put in an array called $itemdb.I                 skip this part to do it shorter. If you want, ask about and I'll post this peace and the                database objet.
                    $this -> price = $itemdb['price'];
                    $this -> stock = $itemdb['stock'];
                }

                function getprice(){
                    return $this->price;
                }

                function substock($units){
                    $newstock = $this->stock - $units;
                    $this->stock = $newstock;
                    return $newstock;
                }
            }



            $item = new items("carrot");
            echo $item->getprice();
            echo "<br/>";
            echo $item->substock("3");
            ?>

If the value in the database is same as the example before.It will output something like: 0.20 12

But from here you have infinite posibilities. Just play more. Give a family item, and creating new methods.

            <?
            class items{

                var $name , $price, $stock, $family;

                function __construct($in_name, $in_price=NULL, $in_stock=NULL, $in_family=NULL){
                    $args = func_num_args();
                    if ($args == 1){
                        $this->name = $in_name;
                        $this->fromdb($in_name);
                    }else{
                        if (!empty($in_name)){$this->name = $in_name;}
                        if (!empty($in_price)){$this->price = $in_price;}
                        if (!empty($in_stock)){$this->stock = $in_stock;}       
                        if (!empty($in_family)){$this->family = $in_family;}        
                    }
                } 

                function fromdb($name){
                    $sql = "SELECT * FROM items WHERE name = '" . $name . "'";
                    //... here we bring from database the item and put in an array called $itemdb. I skip this part to do it shorter. If you want, ask about and I'll post this peace and the database objet.
                    $this -> price = $itemdb['price'];
                    $this -> stock = $itemdb['stock'];
                    $this -> family = $itemdb['family'];
                }

                function getprice(){
                    return $this->price;
                }

                function getfamily(){
                    return $this->family;
                }

                function substock($units){
                    $newstock = $this->stock - $units;
                    $this->stock = $newstock;
                    return $newstock;
                }

                function veggiesinfamily(){
                    $sql = "SELECT count(name),family FROM items WHERE family = '" . $this->family . "'";
                    //... here we bring from database the number of item of a family product in $number. I skip this part to do it shorter. If you want, ask about and I'll post this peace and the database objet.     
                    return $number;
                }

                function familystock(){
                    $sql = "SELECT SUM(stock),family FROM items WHERE family = '" . $this->family . "'";
                    //... here we bring from database the sum of stock items of a family product in $number. I skip this part to do it shorter. If you want, ask about and I'll post this peace and the database objet.     
                    return $number;
                }
            }


            $item = new items("carrot");
            echo "There are " . $item->veggiesinfamily() . $item->getfamily() . " kinds.<br/>";
            echo "There are " . $item->familystock() . " units of " . $item->getfamily();
            ?>

We have also in our database an item: potato, 0.3, 10, roots (name, price, stock, family) If the value in the database have as family roots and as elements carrot and potatoe. The output will be. There is 2 roots kinds. There is 25 units of roots.

And so on. If you load the objet from an external file as item_class.php, and load as include("item_class.php"), can grow your script easily.

Cheers.

Difference between array type and object type in PHP

1 Answers1