PHP array value isn't shown by var_dump but it was fetched.

Question

I wrote some program to check the value in an array.

var_dump($profileuser);//NULL

$profileuser = get_user_to_edit($user_id);//fetch the value of $profileuser

var_dump($profileuser);//does not print the value of $profileuser->user_url 
//nor by print_r($profileuser)

if(isset($profileuser->user_url))
    echo $profileuser->user_url;//printed!!!!How is it possible??

Could somebody can explain how this happened?

background:

I modified the kernel of wordpress.

This happened when I modified the file of wp-admin/user-edit.php.

Doesn't sound plausible, are you sure there are no typos in names? — Hanky Panky
– Hanky Panky, Commented May 3, 2014 at 15:07
Add a call to exit; after var_dump($profileuser); and tell us what you see. — Felipe
– Felipe, Commented May 3, 2014 at 15:35
@FelipeAlmeida I had done what you want me to do. There are too much words that I can not print all of them. However, there is no $profileuser->user_url inside. Only shown the value of $profileuser->data-user_url; but this value is different from $profileuser->user_url. — Ray
– Ray, Commented May 3, 2014 at 15:40
@Hanky웃Panky Pardon that I don't know what does typos means. Can you explain more specific? — Ray
– Ray, Commented May 3, 2014 at 15:42
@Ray typo on Wikipedia. Typos are several typographical errors (spelling errors). — h2ooooooo
– h2ooooooo, Commented May 3, 2014 at 16:29

h2ooooooo · Accepted Answer · 2014-05-03 16:16:25Z

2

You say it's an array, but you're accessing it as an object ($obj->foo rather than $arr['foo']), so it's most likely an object (actually it is - get_user_to_edit returns a WP_User). It could easily contain the magic __get and __isset methods that would lead to this behaviour:

<?php

class User {
    public $id = 'foo';

    public function __get($var) {
        if ($var === 'user_url') {
            return 'I am right here!';
        }
    }

    public function __isset($var) {
        if ($var === 'user_url') {
            return true;
        }

        return false;
    }
}

$user = new User();

print_r($user);
/*
    User Object
    (
        [id] => foo
    )
*/

var_dump( isset($user->user_url) ); // bool(true)
var_dump( $user->user_url ); // string(16) "I am right here!"

DEMO

edited May 3, 2014 at 16:16

answered May 3, 2014 at 16:10

h2ooooooo

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2 Comments

vvanasten Over a year ago

This is what's happening. get_user_to_edit returns a WP_User object, and that object does have magic methods.

Ray Over a year ago

Thanks a lot. I finally figure out!!

Felipe · Accepted Answer · 2014-05-03 16:04:15Z

1

One possibility is that $profileuser is an Object that behaves as an array and not an array itself.

This is possible with interface ArrayAccess. In this case, isset() would return true and you might not see it when you do var_dump($profileuser);.

When you want an object to behave like an array, you need to implement some methods which tell your object what to do when people use it as if it were an array. In that case, you could even create an Object that, when accessed as an array, fetches some webservice and return the value. That may be why you are not seeing those values when you var_dump your variable.

answered May 3, 2014 at 16:04

Felipe

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1 Comment

Ray Over a year ago

Thank you, but @h2ooooooo give me program as an example. Therefore, I gave him the best answer. Thank you also!!

Marcin Nabiałek · Accepted Answer · 2014-05-03 15:11:22Z

0

I thinks it's not possible, I've created test code and var_dump behaves correctly. Are you 100% sure you don't have any typo in your code? I remind variables in PHP are case sensitive

<?php


$profileuser = null;


class User
{
  public $user_url;

}
function get_user_to_edit($id) {
$x = new User();  
  $x->user_url = 'vcv';
  return $x;

}

var_dump($profileuser);//NULL
$user_id = 10;
$profileuser = get_user_to_edit($user_id);//fetch the value of $profileuser

var_dump($profileuser);//does not print the value of $profileuser->user_url 
//nor by print_r($profileuser)

if(isset($profileuser->user_url))
  echo $profileuser->user_url;//printed!!!!How does it possible??

Result is:

null

object(User)[1]
  public 'user_url' => string 'vcv' (length=3)

vcv

answered May 3, 2014 at 15:11

Marcin Nabiałek

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1 Comment

Ray Over a year ago

I used the wordpress version 3.9 and the code was added in the file of wp-admin/user-edit.php line 185. After the var_dump called, there are almost 30 variables shown but not $profileuser->user_url.

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