Question

How can I concatenate a class onto another class in this manner?

class Person { }
$p1 = new Person();
$p2 = new Person();
$p3 = $p1 . $p2;

Keep in mind that I will always know everything in the class that needs to be concatenated ahead of time, so generalization is not an issue.

Answer 1

This will concatenate two objects together assuming they’re the same type

<?php

function combine_objects($obj1, $obj2) {
  if (get_class($obj1) !== get_class($obj2)) {
    throw new Exception('Class mismatch');
  }

  $className = get_class($obj1);
  $newObject = new $className;
  foreach(get_object_vars($obj1) as $key => $value) {
    $newObject->$key = $obj1->$key . $obj2->$key;
  }

  return $newObject;
}

class Person {
  public $first;
  public $last;
  public $id;
}

$john = new Person;
$john->first = 'John';
$john->last = 'Smith';
$john->id = 1;


$mary = new Person;
$mary->first = 'Mary';
$mary->last = 'York';
$mary->id = 5;

$p3 = combine_objects($john, $mary);

var_dump($p3);

/*
object(Person)#3 (3) {
  ["first"]=>
  string(8) "JohnMary"
  ["last"]=>
  string(9) "SmithYork"
  ["id"]=>
  string(2) "15"
}
*/