php中的新DateTime（）vs新的DateTime（'NOW'）

Question

Before I post this question, I searched in several places for answer for this. I really could not find the proper answer.

I evaluated the both way following...

$date = new DateTime()

amd

$date = new DateTime('NOW')

Is it must for the both above give the same result or is there any circumstance they both differ?

Answer 1

If you'll look into DateTime constructor definition you'll see that now is default value for initializing string:

public DateTime::__construct() ([ string $time = "now" [, DateTimeZone $timezone = NULL ]] )

That means both two calls above are always equal. If you'll not specify anything as initializing string, PHP will substitute now implicitly for you.