哪个更快 - $ a。$ b或“$ a $ b”[重复]

Possible Duplicate:
Speed difference in using inline strings vs concatenation in php5?

Note - This was an interview question.

Given,

$a = "some text 1";
$b = "some text 2";

Which one of the following will be faster. Give some reason

$c = $a.$b;

or

$c = "$a$b";

I answered that first one will be faster because two variables are just appended. In the second case however there are variable replacements within a string. But I am not sure.

I would say option A

For basically the same reason you stated

It does not matter. The speed difference will be a few microseconds. It will never have any real-world impact whatsoever.