PHP trait_exists() Function Last Updated : 02 Mar, 2021 Summarize Comments Improve Suggest changes Share Like Article Like Report PHP implements a way to reuse code called Traits. The trait_exists() function in PHP is an inbuilt function that is used to check whether a trait exists or not. This function accepts the traitname and autoload as parameters and returns true if trait exists, false if not, null in case of an error. Syntax : trait_exists ( string $traitname , bool $autoload = ? ) : bool Parameters: This function accepts two parameters as mentioned above and described below. $traitname: This parameter contains the name of the trait.$autoload: This parameter is a boolean value that tells whether to autoload, if not already loaded. Return Value: It returns true, if a trait exists.It returns false, if the trait does not exist.It returns null for any error encountered. Example 1: PHP <?php // Created trait Programming trait Programming { // Declared static instance private static $instance; protected $temp; // Defining static function in trait to Reuse public static function Designing() { self::$instance = new static(); // Magic constant __TRAIT__ in PHP // It gets the class name for the static method called. self::$instance->temp = get_called_class().' '.__TRAIT__; return self::$instance; } } // Checking if 'Programming' Trait exists if ( trait_exists( 'Programming' ) ) { class Initializing { // Reusing trait 'Programming' use Programming; public function text( $strParam ) { return $this->temp.$strParam; } } } echo Initializing::Designing()->text('!!!'); ?> Output: Initializing Programming!!! Example 2: PHP <?php // Creating Base class class Base { public function callBase() { echo 'This is base function!'."<br>"; } } // Creating Trait trait myTrait { public function callBase() { parent::callBase(); echo 'This is trait function!'."<br>"; } } // Using myTrait class myClass extends Base { use myTrait; } $myObject = new myClass(); $myObject->callBase(); // Checking if trait exists if(trait_exists( "myTrait")) { echo "\n myTrait exists! \n"; } else { echo "\n myTrait does not exists! \n"; } ?> Output: This is base function! This is trait function! myTrait exists! Reference : https://www.php.net/manual/en/function.trait-exists.php Comment More infoAdvertise with us Next Article How to check the existence of URL in PHP? C coder36 Follow Improve Article Tags : Web Technologies PHP PHP Programs PHP-function Similar Reads PHP | Check if a variable is a function To determine whether a passed argument is a function or not, Few of the most preferred methods are shown below. Using is_callable() Function: It is an inbuilt function in PHP which is used to verify the contents of a variable in called as a function. It can check that a simple variable contains the 3 min read PHP | Check if a variable is a function To determine whether a passed argument is a function or not, Few of the most preferred methods are shown below. Using is_callable() Function: It is an inbuilt function in PHP which is used to verify the contents of a variable in called as a function. It can check that a simple variable contains the 3 min read How to check the existence of URL in PHP? Existence of an URL can be checked by checking the status code in the response header. The status code 200 is Standard response for successful HTTP requests and status code 404 means URL doesn't exist. Used Functions: get_headers() Function: It fetches all the headers sent by the server in response 2 min read How to check the existence of URL in PHP? Existence of an URL can be checked by checking the status code in the response header. The status code 200 is Standard response for successful HTTP requests and status code 404 means URL doesn't exist. Used Functions: get_headers() Function: It fetches all the headers sent by the server in response 2 min read Difference between isset() and array_key_exists() Function in PHP isset() function The isset() function is an inbuilt function in PHP which checks whether a variable is set and is not NULL. This function also checks if a declared variable, array or array key has null value, if it does, isset() returns false, it returns true in all other possible cases. Syntax: boo 2 min read Difference between isset() and array_key_exists() Function in PHP isset() function The isset() function is an inbuilt function in PHP which checks whether a variable is set and is not NULL. This function also checks if a declared variable, array or array key has null value, if it does, isset() returns false, it returns true in all other possible cases. Syntax: boo 2 min read Like