基于属性合并PHP中的对象

Question

What I am originally trying to do is merge two objects

I have one object like this

{#23 ▼
  +"Name": "Consultation"
  +"ServiceId": "1024"
  +"Price": ".00"
}

Another object

{#362 ▼
  +"StartTime": "9:15AM"
  +"ServiceId": "1024"
}

I am looking for a way to merge these two objects based on it's ServiceId, so I get a single object like this

   {#1 ▼
      +"Name": "Consultation"
      +"ServiceId": "1024"
      +"Price": ".00"
      +"StartTime": "9:15AM"
     }

Of course, if the ServiceId between the two objects do not match, it should not merge.

Any ideas on how to solve the error?

Answer 1

There seems to be two parts to your question. The first part is how to merge the output of two objects returned by json_decode. The second part is how to merge them only if the ServiceId match.

---

Part 1

json_decode produces, by default, objects of class \StdClass. If you want merge two \StdClass objects into a third \StdClass object, you need some judicious casting:

$a = json_decode('{"Name":"Consultation", "ServiceId":"1024", "Price":".00"}');
$b = json_decode('{"StartTime": "9:15AM", "ServiceId": "1024"}');
$c = (object)array_merge((array)$a, (array)$b);
var_dump($c);

Here, $a and $b are \StdClass objects. Cast them to array, merge, then cast them back to \StdClass.

That's a bit of a round-about way to go. So, you can benefit from working with these as arrays from the get-go. json_decode takes an optional second argument, which instructs it to return an array:

$a = json_decode('{"Name":"Consultation", "ServiceId":"1024", "Price":".00"}', true);
$b = json_decode('{"StartTime": "9:15AM", "ServiceId": "1024"}', true);
$c = array_merge($a, $b);
var_dump($c);

This works in arrays the whole time. If you later want $c to be a \StdClass object, you can cast it using $c = (object)$c; as was done in the first example.

See these live on 3v4l.org.

---

Part 2

Presumably, you're going to need some logic that iterates or otherwise pairs these objects together. You don't mention the source, but the logic will look something like this:

if ($a->ServiceId == $b->ServiceId) {
    $c = (object)array_merge((array)$a, (array)$b)
}

If you have a list of objects, and you want to merge them all together, you can use the combinatoric array walk behavior of usort:

$merged = [];
usort($objects, function ($a, $b) use ($merged) {
    $comp = strcmp($a->ServiceId, $b->ServiceId);
    if (0 === $comp) {
        $merged[] = (object)array_merge((array)$a, (array)$b)
    }
    return $comp;
});
var_dump($merged);

This iterates through your list of objects, comparing each. If the ServiceId match, then it merges the two objects and adds it to a list of merged. This will happen for as many objects that share ServiceId as you have in your list.