Comparing two PHP objects - PHP and OBJECTS - php

Question

I have two objects like this.
$array1
stdClass Object (
[BellId] => 2
[BellCode] => BP001
[BellDescription] => SPI SPEED ABNORMAL,CHK BELT
[ControllerId] => 3
[CreatedBy] => 1
[CreatedOn] => 2016-08-19 15:09:25
[ModifiedBy] =>
[ModifiedOn] =>
)
$array2
stdClass Object (
[BellId] => 1
[BellCode] => BP002
[BellDescription] => MCB TRIPPED,CHK MTR SHORT,O/L.
[ControllerId] => 3
[CreatedBy] => 1
[CreatedOn] => 2016-08-19 15:09:25
[ModifiedBy] =>
[ModifiedOn] =>
)
I need to compare this object and get the difference in these two objects only.
I have checked the below links but no use.
Comparing two stdClass Objects
Comparing 2 objects PHP
My Sample code is as follows
function recursive_array_diff($a1, $a2) {
$r = array();
foreach ($a1 as $k => $v) {
if (array_key_exists($k, $a2)) {
if (is_array($v)) {
$rad = recursive_array_diff($v, $a2[$k]);
if (count($rad)) {
$r[$k] = $rad;
}
} else {
if ($v != $a2[$k]) {
$r[$k] = $v;
}
}
} else {
$r[$k] = $v;
}
}
return $r;
}
Can someone help me with the code.

Answer 1

Use array_diff_assoc(); e.g:
<?php
$foo = new stdClass();
$foo->BellId = 1;
$foo->BellDescription = 'foo';
$foo->CreatedBy = 1;
$bar = new stdClass();
$bar->BellId = 2;
$bar->BellDescription = 'bar';
$bar->CreatedBy = 1;
$diff = array_diff_assoc((array) $foo, (array) $bar);
print_r($diff);
array_diff_assoc performs a diff of arrays with additional index check. In your case this is required because you want to perform a key/value diff, not a diff on the values alone.
The above code yields:
Array
(
[BellId] => 1
[BellDescription] => foo
)
Note: you can transparently cast an instance of stdClass() to an array and vice versa:
$arr = ['id' => 1];
$obj = (object) $arr;
$arr = (array) $obj;
// etc.
Hope this helps :)

Answer 2

First convert both objects to arrays:
$arrayA = (array)$objectA;
$arrayB = (array)$objectB;
then just use array_diff to get the difference between arrays
$difference = array_diff($arrayA, $arrayB);
This will return an array containing keys from the first array ($arrayA) and their value, which gives an indication as to what fields are different between the two objects
foreach($difference as $key => $diff) {
echo $objectA->$key;
echo $objectB->$key;
// the above two values will be different
}
Note: array_diff can be used if you know the order of fields in both objects are the same, however it's probably best to use array_diff_assoc here, as this offers an additional index check.

Answer 3

With array_udiff_assoc you can compare the items as you like using a callback. Of course, you need to cast the objects to arrays:
$d = array_udiff_assoc((array)$array1, (array)$array2, function ($x, $y) {
if (! (is_scalar($x) && is_scalar($y))) {
trigger_error("skipping non-scalar members!", E_USER_WARNING);
// you might want to handle this in the app-specific way
}
if (is_numeric($x) && is_numeric($y))
return $x - $y;
return strcmp($x, $y);
});
var_dump($d);
where $x and $y are the items from the arrays being compared.
Sample output
array(3) {
["BellId"]=>
int(2)
["BellCode"]=>
string(5) "BP001"
["BellDescription"]=>
string(27) "SPI SPEED ABNORMAL,CHK BELT"
}
This is a very flexible way. You can put your own comparison logic into the callback. For instance, you might want to compare instances of classes:
static $date_fmt = 'YmdHis';
if ($x instanceof DateTime)
$x = $x->format($date_fmt);
if ($y instanceof DateTime)
$y = $y->format($date_fmt);