Question

I have an array of values that will get updated periodically. When the array is updated, I want to perform an action using the new values in the updated array.

$old_node->field_name[0]['value'] = 'red'
$old_node->field_name[1]['value'] = 'yellow'
$old_node->field_name[2]['value'] = 'blue'


$updated_node->field_name[0]['value'] = 'green',
$updated_node->field_name[1]['value'] = 'red',
$updated_node->field_name[2]['value'] ='purple',
$updated_node->field_name[3]['value'] = 'blue',

So the values of ‘green’ and ‘purple’ are the new values in the new array. I need to run each of the values that are ADDED to the new array through a function. Something like:

foreach(of the newly added values that are in the new array){
 //do stuff;
}

Some values may be deleted when the array is updated, so the the key=>value pairs could change.

I’ve tried:

foreach($updated_node->field_name as $new_value){
    if(!in_array($new_value['value'], $old_node->field_name) && $new_value['value'] !== NULL){

    //Do stuff; 

        } 
    } 

But that doesn’t work. I’ve also tried picking out new values with array_diff and array_intersect, but that’s not working either.

Answer 1

use array_diff()

$old_array = array(
          0 => 'red',
          1 =>'yellow',
          2 => 'blue'
);

$new_array = array(
          0 => 'green',
          1 => 'red',
          2 =>'purple',
          4 => 'blue'
);

$diff = array_diff($new_array, $old_array);

print_r($diff);

/*
Array
(
    [0] => green
    [2] => purple
)
*/

for your new code

$old_node->field_name[0]['value'] = 'red';
$old_node->field_name[1]['value'] = 'yellow';
$old_node->field_name[2]['value'] = 'blue';


$updated_node->field_name[0]['value'] = 'green';
$updated_node->field_name[1]['value'] = 'red';
$updated_node->field_name[2]['value'] = 'purple';
$updated_node->field_name[3]['value'] = 'blue';

$diff = array();
foreach($updated_node->field_name as $num => $field){
    $tmpval = false;
    foreach($old_node->field_name as $old){
        if($field['value'] == $old['value']){
            $tmpval = true;
        }
    }
    if(!$tmpval){
        $diff[$num] = $field['value'];    
    }
}

print_r($diff);

/*
Array
(
    [0] => green
    [2] => purple
)
*/