in_array - 'in_object' equivalent? - php

Question

Is there such a function like in_array, but can be used on objects?

Answer 1

Nope, but you can cast the object to an array and pass it into in_array().
$obj = new stdClass;
$obj->one = 1;
var_dump(in_array(1, (array) $obj)); // bool(true)
That violates all kinds of OOP principles though. See my comment on your question and Aron's answer.

Answer 2

First of all, arrays and objects are quite different.
A PHP object can not be iterated through like an array, by default. A way to implement object iteration is to implement the Iterator interface.
Concerning your specific question, you probably want to take a look at the ArrayAccess interface:
class obj implements ArrayAccess {
private $container = array();
public function __construct() {
$this->container = array(
"one" => 1,
"two" => 2,
"three" => 3,
);
}
public function offsetSet($offset, $value) {
if (is_null($offset)) {
$this->container[] = $value;
} else {
$this->container[$offset] = $value;
}
}
public function offsetExists($offset) {
return isset($this->container[$offset]);
}
public function offsetUnset($offset) {
unset($this->container[$offset]);
}
public function offsetGet($offset) {
return isset($this->container[$offset]) ? $this->container[$offset] : null;
}
}
Now you can access your object like an array in the following manner:
$object = new obj();
var_dump(isset($obj['two'])); // exists!
var_dump(isset($obj['foo'])); // does not exist
Before you go crazy on this though, please consider why you are actually trying to do this and take a look at the examples at php.net.
Option 2: when you are simply trying to see if a property exists, you can use property_exists() for this:
class foo {
public $bar = 'baz';
}
$object = new foo();
var_dump(property_exists($object, 'bar')); // true

Answer 3

You could cast the object to an array:
$obj = new stdClass();
$obj->var = 'foobar';
in_array( 'foobar', (array)$obj ); // true

Answer 4

function in_object($needle, $haystack) {
return in_array($needle, get_object_vars($haystack));
}

Answer 5

It's unbelievable how all the people miss the point of the usefulness of an in_object PHP method! Here is what I came up with, it is very useful, and you will see why!
Here is a simple function I wrote which will check if a value can be found within an object.
<?php
// in_object method
// to check if a value in an object exists.
function in_object($value,$object) {
if (is_object($object)) {
foreach($object as $key => $item) {
if ($value==$item) return $key;
}
}
return false;
}
?>
This is very useful if an object has been created dynamically (especially from external code, which you don't control, as in an application-plugin, CMS, etc), and you don't know the object's properties.
The above function will return the property, so you will be able to use it in your code later on.
Here is a very good basic example of how useful this function is!
<?php
class My_Class {
function __construct($key, $value) {
$this->$key = $value;
// As you can see, this is a dynamic class, its properties and values can be unknown...
}
}
function in_object($value,$object) {
if (is_object($object)) {
foreach($object as $key => $item) {
if ($value==$item) return $key;
}
}
return false;
}
function manipulate_property($value,$object) {
if ($property = in_object($value,$object)) {
// value found. I can now use this property.
// I can simply echo'it (makes no sense, as I could instead simply echo "value")
echo "<br />I found the property holding this value: ".$object->$property;
// or (here comes the good part)
// change the property
$object->$property = "This is a changed value!";
echo "<br />I changed the value to: ".$object->$property;
// or return it for use in my program flow
return $property;
} else {
echo "Value NOT FOUND!<br />";
return false;
}
}
// imagine if some function creates the class conditionally...
if ( 1 == 1) {
$class = new My_Class("property","Unchanged Value");
} else {
$class = new My_Class("property","Some Other Value");
}
// now let's check if the value we want exists, and if yes, let's have some fun with it...
$property = manipulate_property("Unchanged Value",$class);
if ($property) {
$my_variable = $class->$property;
echo "<br />This is my variable now:".$my_variable;
} else $my_variable = $some_other_variable;
?>
Just run it to see for yourself!

Answer 6

I don't recommend it, because it's very bad practice but you can use get_object_vars.
Gets the accessible non-static properties of the given object according to scope.
There are other limitations you should refer to the documentation to see if it is suitable for you.
if(in_array('find me', get_object_vars($obj)))

Answer 7

This is the most efficient and correct solution. With some modifications it could be applied to check any data type present in any object.
if(gettype($object->var1->var2) == "string"){
echo "Present";
}