PHP | ReflectionParameter isDefaultValueConstant() Function

The ReflectionParameter::isDefaultValueConstant() function is an inbuilt function in PHP which is used to return TRUE if the default value is constant, and FALSE otherwise.

Syntax:

bool ReflectionParameter::isDefaultValueConstant ( void )

Parameters: This function does not accept any parameters.

Return Value: This function returns TRUE if the default value is constant, and FALSE otherwise.

Below programs illustrate the ReflectionParameter::isDefaultValueConstant() function in PHP:
Program 1:

<?php

// Initializing a user-defined class Company1
class Company1
{
    function GFG($Full_Name = GeeksforGeeks){}
}

// Initializing a subclass Company2
class Company2 extends Company1
{
}

// Using the ReflectionParameter over the above class
$A = new ReflectionParameter(['Company2', 'GFG'], 0);

// Calling the isDefaultValueConstant() function
$B = $A->isDefaultValueConstant();

// Getting TRUE if the default value is
// constant, and FALSE otherwise.
var_dump($B);
?>

Output:

bool(true)

Program 2:

<?php

// Initializing some user-defined classes
class Department1
{
    function HR( $Full_Name = Human_Resource){}
}
class Department2
{
    function Coding( $Parameter2, $Par3 = 'Parameter3'){}
}
class Department3
{
    function Marketing( $Parameter4, $Parameter5 = Digital_Marketing){}
}

// Using the ReflectionParameter over the above classes
$A = new ReflectionParameter(['Department1', 'HR'], 0);
$B = new ReflectionParameter(['Department2', 'Coding'], 1);
$C = new ReflectionParameter(['Department3', 'Marketing'], 1);

// Calling the isDefaultValueConstant() function and
// getting TRUE if the default value is
// constant, and FALSE otherwise.
var_dump($A->isDefaultValueConstant());
var_dump($B->isDefaultValueConstant());
var_dump($C->isDefaultValueConstant());
?>

Output:

bool(true)
bool(false)
bool(true)

Reference: https://www.php.net/manual/en/reflectionparameter.isdefaultvalueconstant.php