PHP : ReflectionParameter, isOptional vs isDefaultValueAvailable

Question

What is the difference between two. both of these are working exactly in a same way.

public static function getArgsArray($reflectionMethod,$argArray){
    $arr = array();
    foreach($reflectionMethod->getParameters() as $key => $val){
        $arr[$val->getName()] = isset($argArray[$val->getName()]) ?
        $argArray[$val->getName()] : (isset($_REQUEST[$val->getName()])
                ? $_REQUEST[$val->getName()] : ($val->*isDefaultValueAvailable()*  ? $val->getDefaultValue() : NULL));
    }
    return $arr;
}

Be very careful with those nested ternary statements. Nothing but trouble IMHO — Phil
– Phil, Commented May 21, 2014 at 5:51
They're just hard to read and the logic process is not always clear. See the note here ~ php.net/manual/language.operators.comparison.php#example-137 — Phil
– Phil, Commented May 21, 2014 at 5:54

Pavel Vlasov · Accepted Answer · 2024-06-20 18:07:42Z

12

Good question. Consider this example

function foo($foo = 'foo', $bar) {}

For the $foo parameter, isDefaultValueAvailable() would understandably return true however isOptional() would return false as the next parameter ($bar) has no default value and is therefore not optional. To support the non-optional $bar parameter, $foo must itself be non-optional.

Hope this makes sense ;)

I've noted that behaviour differs across PHP versions. 5.5 returns the above whereas 5.4 says parameter 1 is both not optional and has no default value.

Demo: https://3v4l.org/qgbh7

edited Jun 20, 2024 at 18:07

Pavel Vlasov

4,4106 gold badges46 silver badges55 bronze badges

answered May 21, 2014 at 5:39

Phil

166k25 gold badges265 silver badges269 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

LNT Over a year ago

You mean, in your example, $foo='foo' will make sense if i call it like this foo(null,'hello') but not foo('helllo')

Phil Over a year ago

@LNT Well, that would just set $foo to null. It's a silly way to write a function but not impossible, therefore the reflection utils need to differentiate

ZhukV · Accepted Answer · 2014-05-21 05:54:55Z

The function isDefaultValueAvailable can work only on user defined function, and not work on system functions (PHP core).

So, as example:

class Foo
{
    public function foo($var = null)
    {
    }
}

// Get the "var" argument in method Foo::foo
$refParameter = (new ReflectionClass('Foo'))->getMethod('foo')->getParameters()[0];

print "User function Foo::foo:\n\n";

print 'Optional: ' . ($refParameter->isOptional() ? 'true' : 'false') . "\n";
print 'Default available: ' . ($refParameter->isDefaultValueAvailable() ? 'true' : 'false') . "\n";
if ($refParameter->isDefaultValueAvailable()) {
    print 'Default value: ' . var_export($refParameter->getDefaultValue(), 1);
}

print "\n\n";

print "System function substr\n\n";

// Get the "length" parameter from function substr
$refParameter = (new \ReflectionFunction('substr'))->getParameters()[2];

print 'Optional: ' . ($refParameter->isOptional() ? 'true' : 'false') . "\n";
print 'Default available: ' . ($refParameter->isDefaultValueAvailable() ? 'true' : 'false') . "\n";
if ($refParameter->isDefaultValueAvailable()) {
    print 'Default value: ' . var_export($refParameter->getDefaultValue(), 1);
}

print "\n\n";

And, this code shows: your can get default value only from user defined function and can not get from system function (substr as example). But the method isOptional returned true in user defined function and system function.

Conclusion:

If your want check the parameter is optional, your must use isOptional method.
You can get the default value only from the user defined function.
You can not use method isDefaultValueAvailable on system (PHP) defined function.

Source: https://github.com/php/php-src/blob/ccf863c8ce7e746948fb060d515960492c41ed27/ext/reflection/php_reflection.c#L2536-L2573

Thanks, got your point, I m only using it for user defined fucntions

Collectives™ on Stack Overflow

PHP : ReflectionParameter, isOptional vs isDefaultValueAvailable

2 Answers 2

2 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related