PHP | ReflectionClass hasConstant() Function

The ReflectionClass::hasConstant() function is an inbuilt function in PHP which is used to check the specified constant is present or not.

Syntax:

bool ReflectionClass::hasConstant( string $name )

Parameters: This function accepts a single parameter $name which holds the name of the defined constant.

Return Value: This function returns TRUE if the constant is define, FALSE otherwise.

Below programs illustrate the ReflectionClass::hasConstant() function in PHP:

Program 1:

<?php

// Defining a user-defined class Company
class Company {
    const c1 = 'GeeksforGeeks';
}

// Using the ReflectionClass over the
// defined user-defined class Company
$constant = new ReflectionClass("Company");

// Calling the hasConstant() function
$const = $constant->hasConstant("c1");

// Getting the value TRUE or FALSE
var_dump($const);
?>

Output:

bool(true)

Program 2:

<?php

// Defining an empty class
class Company {
}

// Using the ReflectionClass over the
// defined user-defined class Company
$constant = new ReflectionClass("Company");

// Calling the hasConstant() function and
// getting the value TRUE or FALSE
var_dump($constant->hasConstant("c1"));
?>

Output:

bool(false)

Reference: https://secure.php.net/manual/en/reflectionclass.hasconstant.php