PHP Call non static function with static way

Question

What happens when we calling non-static functions with static way?
Like this :

class test
{
    public function hello()
    {
        return "say hello";
    }
}

class foo
{
    public function __construct()
    {
        echo test::hello();
    }
}

$foo = new foo();

Answer 1

You will get Strict standards: Non-static method test::hello() should not be called statically

and your Class declaration is not good, right way is this

class test
{
    public function hello()
    {
        return "say hello";
    }
}

class foo
{
    public function __construct()
    {
        echo test::hello();
    }
}

$foo = new foo();

Laravel uses Facade to give illusion that you are using static method, you can also use Facade to call method like test::hello();

Here is a good read on Facade

Answer 2

Fast answer: You get a strict warning.

More details: If the variable $this is used in the function called it refers to the object where the function got called, not the class containing the function itself.

Strict standards: Non-static method hello should not be called statically, assuming $this from incompatible context