php object : get value of attribute by computed name

Question

hi simple question -

How do I access an attribute of an object by name, if i compute the name at runtime?

Ie. i loop over keys and want to get each value of the attributes "field_".$key

In python there is getattribute(myobject, attrname)

It works, of course, with eval("$val=$myobject->".$myattr.";"); but IMO this is ugly!!

TIA florian

Answer 1

$myobject->{'field_'.$key}

Answer 2

$val = $myobject->$myattr;

Answer 3

Keep always in mind that a very powerful feature of PHP is its Variable Variables

You can use

$attr = 'field' . $key;
$myobject->$attr;

or more concisely, using curl brackets

$myobject->{'field_'.$key};

Answer 4

With reflection:

$reflectedObject = new ReflectionObject($myobject);
$reflectedProperty = $reflectedObject->getProperty($attrName);
$value = $reflectedProperty->getValue($myobject);

This works only if the accessed property is public, if it's protected or private an exception will occurr.