Where is the best place to declare private properties?

Question

PHP

Hello.
Tell me where you define private properties in the class.
At the beginning?

class A 
{
    private $items;

    public function doSomthing()
    {
        return 'I done';
    }

    ...

   public function implodeItems()
   {
       return implode($this->items);
    }
}

Or somewhere in the class when you enter a variable?

class A 
{
    public function doSomthing()
    {
        return 'I done';
    }

    ...
   
   private $items;

   public function setItems(array $value)
   {
       $this->items = $value;
   } 

   public function implodeItems()
   {
       return implode($this->items);
   }
}

Answer 1

Variables are usually declared at the beginning of the file (and it doesn't matter if it's a class or just a file with functions)

Answer 2

At the beginning. The view may blur and miss the property declaration. And if they are all defined at the beginning, then, firstly, at the first glance at the class, it becomes clear what it operates with, and, secondly, if you forgot the property signature, then you just look at the beginning of the file and easily find it.