<?php

$str = '6 bedroom ground floor flat in Edinburgh

house in Manchester

3 bedroom apartment

';

//preg_match_all("#(((\d+)\s+bedroom)\s+)?(.+?)\s(in\s+(\w+))?\n#i", $str, $m);
preg_match_all("#(((?<bedroomCount>\d+)\s+bedroom)\s+)?(?<type>.+?)\s(in\s+(?<city>\w+))?\n#i", $str, $m);
var_dump($m);


/*
array(10) {
  [0]=>
  array(3) {
    [0]=>
    string(41) "6 bedroom ground floor flat in Edinburgh
"
    [1]=>
    string(20) "house in Manchester
"
    [2]=>
    string(21) "3 bedroom apartment

"
  }
  [1]=>
  array(3) {
    [0]=>
    string(10) "6 bedroom "
    [1]=>
    string(0) ""
    [2]=>
    string(10) "3 bedroom "
  }
  [2]=>
  array(3) {
    [0]=>
    string(9) "6 bedroom"
    [1]=>
    string(0) ""
    [2]=>
    string(9) "3 bedroom"
  }
  ["bedroomCount"]=>
  array(3) {
    [0]=>
    string(1) "6"
    [1]=>
    string(0) ""
    [2]=>
    string(1) "3"
  }
  [3]=>
  array(3) {
    [0]=>
    string(1) "6"
    [1]=>
    string(0) ""
    [2]=>
    string(1) "3"
  }
  ["type"]=>
  array(3) {
    [0]=>
    string(17) "ground floor flat"
    [1]=>
    string(5) "house"
    [2]=>
    string(9) "apartment"
  }
  [4]=>
  array(3) {
    [0]=>
    string(17) "ground floor flat"
    [1]=>
    string(5) "house"
    [2]=>
    string(9) "apartment"
  }
  [5]=>
  array(3) {
    [0]=>
    string(12) "in Edinburgh"
    [1]=>
    string(13) "in Manchester"
    [2]=>
    string(0) ""
  }
  ["city"]=>
  array(3) {
    [0]=>
    string(9) "Edinburgh"
    [1]=>
    string(10) "Manchester"
    [2]=>
    string(0) ""
  }
  [6]=>
  array(3) {
    [0]=>
    string(9) "Edinburgh"
    [1]=>
    string(10) "Manchester"
    [2]=>
    string(0) ""
  }
}