Title: function_exists
Last modified: August 20, 2016

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# function_exists

 *  [Rafael Dourado](https://wordpress.org/support/users/rdourado/)
 * (@rdourado)
 * [14 years, 1 month ago](https://wordpress.org/support/topic/function_exists/)
 * Do I have to use if ( ! function_exists… before every function in functions.php?
   
   Twentyeleven theme use it, but is it necessary? Does it improves performance?

Viewing 2 replies - 1 through 2 (of 2 total)

 *  [esmi](https://wordpress.org/support/users/esmi/)
 * (@esmi)
 * [14 years, 1 month ago](https://wordpress.org/support/topic/function_exists/#post-2694933)
 * No. It is only required if you want your theme to be child-theme friendly.
 *  Thread Starter [Rafael Dourado](https://wordpress.org/support/users/rdourado/)
 * (@rdourado)
 * [14 years, 1 month ago](https://wordpress.org/support/topic/function_exists/#post-2694988)
 * Thank you!

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘function_exists’ is closed to new replies.

## Tags

 * [functions](https://wordpress.org/support/topic-tag/functions/)

 * 2 replies
 * 2 participants
 * Last reply from: [Rafael Dourado](https://wordpress.org/support/users/rdourado/)
 * Last activity: [14 years, 1 month ago](https://wordpress.org/support/topic/function_exists/#post-2694988)
 * Status: not a support question

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