What is the difference between static functions and a function outside a class in PHP?

Question

I need to have a way to get something from the database, but I do not understand the difference between static and normal functions in PHP.

Code example

class Item {
    public static function getDetail($arg) {
        $detail = $this->findProductId($arg);   
        return $detail;
    }

    private function findProductId($id) {
        //find product_id in database where id = $arg
        //return detail of product
    }
}

and function outside the class

function getDetail($arg) {
    $detail = findProductId($arg);
    return $detail;
}

If I use $item = Item::getDetail(15);and $item = getDetail(15);- they are the same.

• What is the difference between static and function outside the class?
• If this is the difference, how to use static functions and functions outside the class? (I would appreciate a really simple example.)
• What are the performance properties between static and function outside the class? What's better?

Answer 1

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