CODEWITHSUNDEEP
php
user198729
user198729

Reputation: 63626

Is there any difference between __DIR__ and dirname(__FILE__) in PHP?

It looks the same for me,but I'm not sure,

because there are many projects that uses dirname(__FILE__).

Upvotes: 144

Views: 75245

Answers (1)

Pascal MARTIN
Pascal MARTIN

Reputation: 400952

Their result is exactly the same ; so, no difference on that.


For example, the two following lines :

var_dump(dirname(__FILE__));
var_dump(__DIR__);

Will both give the same output :

string '/home/squale/developpement/tests/temp' (length=37)


But, there are at least two differences :

  • __DIR__ only exists with PHP >= 5.3
    • which is why dirname(__FILE__) is more widely used
  • __DIR__ is evaluated at compile-time, while dirname(__FILE__) means a function-call and is evaluated at execution-time
    • so, __DIR__ is (or, should be) faster.


As, as a reference, see the Magic constants section of the manual (quoting) :

__DIR__ : The directory of the file.
If used inside an include, the directory of the included file is returned.
This is equivalent to dirname(__FILE__).
This directory name does not have a trailing slash unless it is the root directory.
(Added in PHP 5.3.0.)

Upvotes: 227

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