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php – How to check If an object is empty?

Posted by: admin July 12, 2020 Leave a comment

Questions:

How can I check if a PHP object is empty (i.e. has no properties)? The built-in empty() does not work on objects according the doc:

5.0.0 Objects with no properties are no longer considered empty.
How to&Answers:

ReflectionClass::getProperties

http://www.php.net/manual/en/reflectionclass.getproperties.php

class A {
    public    $p1 = 1;
    protected $p2 = 2;
    private   $p3 = 3;
}

$a = new A();
$a->newProp = '1';
$ref = new ReflectionClass($a);
$props = $ref->getProperties();

// now you can use $props with empty
echo empty($props);

print_r($props);

/* output:

Array
(
    [0] => ReflectionProperty Object
        (
            [name] => p1
            [class] => A
        )

    [1] => ReflectionProperty Object
        (
            [name] => p2
            [class] => A
        )

    [2] => ReflectionProperty Object
        (
            [name] => p3
            [class] => A
        )

)

*/

Note that newProp is not returned in list.

get_object_vars

http://php.net/manual/en/function.get-object-vars.php

Using get_object_vars will return newProp, but the protected and private members will not be returned.


So, depending on your needs, a combination of reflection and get_object_vars may be warranted.

Answer:

Here is the solution:;

$reflect = new ReflectionClass($theclass);
$properties = $reflect->getProperties();

if(empty($properties)) {
    //Empty Object
}

Answer:

Can you elaborate this with some code? I don’t get what you’re trying to accomplish.

You could anyhow call a function on the object like this:

public function IsEmpty()
{
    return ($this->prop1 == null && $this->prop2 == null && $this->prop3 == null);
}

Answer:

I believe (not entirely sure) that you can override the isset function for objects.
In the class, you can provide an implemention of __isset() and have it return accordingly to which properties are set.

Try reading this:
http://www.php.net/manual/en/language.oop5.overloading.php#language.oop5.overloading.members