Check if variable isset in object

Question

I have object:

class Obj
{
    public $foo;
    public $bar;
}

$obj = new Obj();

print_R($obj);

Output:

Obj Object
(
    [foo] => 
    [bar] => 
)

But

var_dump(isset($obj->foo));

output bool(false).

How to check is variable set in object?

Solution 1

Because

$foo = null;
var_dump(isset($foo)); // false

Maybe you want check it with property_exists or ReflectionClass::hasProperty

Solution 2

You should use a combination of both isset and property_exists:

if (property_exists($obj,$foo) && isset($obj->$foo)) {
   // use $obj->foo
}

A property may exist with nothing set into it, which won't be accessible as expected.

Comments

[Narek]

Thanks, didn't know about null.