How to find index of object in php array?

$found = false;  
foreach($values as $key => $value) {
    if ($value->id == 4) {
        $found = true;
        break;
    }
}

if ($found) unset($values[$key]);

This is considered to be faster then any other solution since we only iterate the array to until we find the object we want to remove.

Note: You should not remove an element of an array while iterating so we do it afterwards here.

foreach($parentObj AS $key=>$element){
  if ($element->id == THE_ID_YOU_ARE_LOOKING_FOR){
    echo "Gottcha! The index is - ". $key;
  }
}

$parentObj is obviously your root array - the one that holds all the others.

We use the foreach loop to iterate over each item and then test it's id property against what ever value you desire. Once we have that - the $key that we are on is the index you are looking for.

use array_search:

$a = new stdClass;
$b = new stdClass;
$a->id = 1;
$b->id = 2;

$arr = array($a, $b);
$index = array_search($b, $arr);

echo $index;
// prints out 1