How to check for object value = empty array?

Question

Iterating through an object... API response... for some strange reason, certain empty values are coming up as an empty array... i.e.

$foo->bar = array()

or

$foo->bar = array(0)

But when I try to check with:

if ( empty($foo->bar) )

Or even:

if ( is_array($foo->bar) )

It's not catching it. I've been converting the whole object to an array to get around this, which works, but is costing performance.

Is there something I'm missing here?

EDIT:

Going back, it looks like I mixed up my array with my object. What I NEED to check for is an empty value in a response such as:

[1] => SimpleXMLElement Object
    (
        [RecordID] => 14
        [SomethingID] => 1
        [SomethingName] => OKAY
        [Integer] => 0
        [String] => String
        [AnotherInteger] => 1
        [Empty] => SimpleXMLElement Object
            (
            )

        [SomethingElseID] => 0
    )

How do I check if $object->Empty is EMPTY?

EDIT:

var_dump shows:

object(SimpleXMLElement)#1343 (8) { 

    ["RecordID"]=> string(2) "14" 
    ["SomethingID"]=> string(1) "1" 
    ["SomethingName"]=> string(4) "OKAY" 
    ["Integer"]=> string(1) "0" 
    ["String"]=> string(6) "String" 
    ["AnotherInteger"]=> string(1) "1" 
    ["Empty"]=> object(SimpleXMLElement)#1355 (0) { } 
    ["SomethingElseID"]=> string(1) "0" 

}

array(0) isn't an empty array, and empty($arr) does work. — user2864740
– user2864740, Commented May 9, 2014 at 23:05
Wait, what are the expected and actual outputs for each of the arrays (array() and array(0))? — NullUserException
– NullUserException, Commented May 9, 2014 at 23:06
array(0) has only come up once or twice, randomly... yet empty($array) is NOT producing the desired result. empty($array), having output the object and seen that the value of the array is indeed empty, does not produce a TRUE response when checking with empty(). — FurryWombat
– FurryWombat, Commented May 9, 2014 at 23:11

Marcin Orlowski · Accepted Answer · 2014-05-09 23:20:48Z

2

Use empty($array) (docs) to determine if you array is empty.

EDIT

Yes, I noticed OP stated he uses empty() but you can always do something like:

function isArrayEmpty($arr) {
   return (count($arr) == 0);
}

for verification purposes. empty() is (theoretically) the way to go. And you can always use var_dump() or print_r() to inspect why empty() claims array is not empty while you bet it should be.

Also @chameleon answer lead me to this: https://bugs.php.net/bug.php?id=24915 - if your class is using __get() then using count() instead of empty() may be the workaround.

edited May 9, 2014 at 23:20

answered May 9, 2014 at 23:08

Marcin Orlowski

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3 Comments

NullUserException Over a year ago

OP states they are using empty()

Marcin Orlowski Over a year ago

Then either array is not empty or OP found a bug in PHP.

FurryWombat Over a year ago

seriously doubt it's a bug. digging deeper. driving me nuts right now... maybe need to rest the eyes a bit.

Ozair Patel · Accepted Answer · 2014-05-09 23:15:20Z

0

You can also use foreach to determine if an array is empty, although I recommend @Marcin's method

foreach($array as $key => $value){
  if(empty($value)){
    unset($array[$key]);
  }
}

answered May 9, 2014 at 23:15

Ozair Patel

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Comments

charmeleon · Accepted Answer · 2014-05-09 23:27:42Z

0

If your object uses the magical __get() function to access an object's properties, an empty() check will fail unless you are using PHP 5.5+.

From the docs:

Prior to PHP 5.5, empty() only supports variables; anything else will result in 
a parse error. In other words, the following will not work: empty(trim($name)).

If you use the magical method to access the property, it is like doing empty($object->__get($property))

EDIT: Note that though the docs mention that it results in a parse error, I've never actually seen it result in a PHP error, I believe it simply returns false

edited May 9, 2014 at 23:27

answered May 9, 2014 at 23:16

charmeleon

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