Missing argument 1 for Product::__construct() - php

Question

So I have this code:
<?php
class Product
{
public $name = 'default_name';
public $price = 0;
public $desc = 'default description';
function __construct($name, $price, $desc){
$this->name = $name;
$this->price = $price;
$this->desc = $desc;
}
public function getInfo(){
return "Product Name: " . $this->name;
}
}
$p = new Product();
$shirt = new Product("Space Juice T-Shirt", 20, "Awesome Grey T-Shirt");
$soda = new Product("Space Juice Soda", 2, "Grape Flavored Thirst Mutilator");
echo $shirt->getInfo();
?>
and PHP reports "Missing argument 1 for Product::__construct()" error. I got this example in one of the leading PHP courses and I'm confused because there seems to be an error somewhere inside this simple code. Help would be much appriciated.

Answer 1

In your code, if you are going to create an instance of Product, passing the parameters are mandatory. Whereas, you already have the default values. So, Make it safe:
<?php
class Product
{
public $name = 'default_name';
public $price = 0;
public $desc = 'default description';
function __construct($name = null, $price = null, $desc = null){
$this->name = $name ?: $this->name;
$this->price = $price ?: $this->price;
$this->desc = $desc ?: $this->desc;
}
public function getInfo(){
return "Product Name: " . $this->name;
}
}
$p = new Product();
$shirt = new Product("Space Juice T-Shirt", 20, "Awesome Grey T-Shirt");
$soda = new Product("Space Juice Soda", 2, "Grape Flavored Thirst Mutilator");
echo $shirt->getInfo();
?>

Answer 2

Your construct doesn't allow nulls for your variables, and so
$p = new Product();
is causing the problem. It's expecting some value, even if it's just empty strings, for $name, $price and $desc.
If you change your construct function to this:
function __construct($name = 'default_name', $price = 0, $desc = 'default description'){
$this->name = $name;
$this->price = $price;
$this->desc = $desc;
}
then it shouldn't throw that error any more.