Cannot sort array alphabetically

Question

I need to sort an array alphabetically after that I add new items to it, the problem's that sort function is not working as expected:

$opts = "Air conditioning, Balcony, Bedding, Concrete flooring, Garage, Garden, Heating, Internet, Laundry, Outdoor Kitchen, Parking, Swimming Pool, TV Cable, Tennis courts, Trees,Gym,access to private beach,access to private beach club,air conditioning,air heating,alfresco dining,alfresco shower,american style coffee maker,barbecue,bath amenities,breakfast patio area,cooking area,dishwasher,doorman,dryer machine,dvd player,hairdryer,heated pool,hi fi system,large fridge,laundry area,living room,maid service,main terrace,microwave,modern kitchen,oven,panoramic terrace,pool,pool with jet stream,refrigerator,safe,sat tv,solarium,terrace,washing machine,wi fi";
$opts = explode(',', $opts);
$test = array('hello world');

$updated_opts = array_merge($test, $opts);
sort($updated_opts);
var_dump($updated_opts);

the output is the following:

array(53) {
  [0]=>
  string(8) " Balcony"
  [1]=>
  string(8) " Bedding"
  [2]=>
  string(18) " Concrete flooring"
  [3]=>
  string(7) " Garage"
  [4]=>
  string(7) " Garden"
  [5]=>
  string(8) " Heating"
  [6]=>
  string(9) " Internet"
  [7]=>
  string(8) " Laundry"
  [8]=>
  string(16) " Outdoor Kitchen"
  [9]=>
  string(8) " Parking"
  [10]=>
  string(14) " Swimming Pool"
  [11]=>
  string(9) " TV Cable"
  [12]=>
  string(14) " Tennis courts"
  [13]=>
  string(6) " Trees"
  [14]=>
  string(16) "Air conditioning"
  [15]=>
  string(3) "Gym"
  [16]=>
  string(23) "access to private beach"
  [17]=>
  string(28) "access to private beach club"
  [18]=>
  string(16) "air conditioning"
  [19]=>
  string(11) "air heating"
  [20]=>
  string(15) "alfresco dining"
  [21]=>
  string(15) "alfresco shower"
  [22]=>
  string(27) "american style coffee maker"
  [23]=>
  string(8) "barbecue"
  [24]=>
  string(14) "bath amenities"
  [25]=>
  string(20) "breakfast patio area"
  [26]=>
  string(12) "cooking area"
  [27]=>
  string(10) "dishwasher"
  [28]=>
  string(7) "doorman"
  [29]=>
  string(13) "dryer machine"
  [30]=>
  string(10) "dvd player"
  [31]=>
  string(9) "hairdryer"
  [32]=>
  string(11) "heated pool"
  [33]=>
  string(11) "hello world"
  [34]=>
  string(12) "hi fi system"
  [35]=>
  string(12) "large fridge"
  [36]=>
  string(12) "laundry area"
  [37]=>
  string(11) "living room"
  [38]=>
  string(12) "maid service"
  [39]=>
  string(12) "main terrace"
  [40]=>
  string(9) "microwave"
  [41]=>
  string(14) "modern kitchen"
  [42]=>
  string(4) "oven"
  [43]=>
  string(17) "panoramic terrace"
  [44]=>
  string(4) "pool"
  [45]=>
  string(20) "pool with jet stream"
  [46]=>
  string(12) "refrigerator"
  [47]=>
  string(4) "safe"
  [48]=>
  string(6) "sat tv"
  [49]=>
  string(8) "solarium"
  [50]=>
  string(7) "terrace"
  [51]=>
  string(15) "washing machine"
  [52]=>
  string(5) "wi fi"
}

Answer 1

Apply trim to remove spaces in the beginning of the words:

$opts = "Air conditioning, Balcony, Bedding, Concrete flooring, Garage, Garden, Heating, Internet, Laundry, Outdoor Kitchen, Parking, Swimming Pool, TV Cable, Tennis courts, Trees,Gym,access to private beach,access to private beach club,air conditioning,air heating,alfresco dining,alfresco shower,american style coffee maker,barbecue,bath amenities,breakfast patio area,cooking area,dishwasher,doorman,dryer machine,dvd player,hairdryer,heated pool,hi fi system,large fridge,laundry area,living room,maid service,main terrace,microwave,modern kitchen,oven,panoramic terrace,pool,pool with jet stream,refrigerator,safe,sat tv,solarium,terrace,washing machine,wi fi";
$opts = explode(',', $opts);
// here
$opts = array_map('trim', $opts);
$test = array('hello world');

$updated_opts = array_merge($test, $opts);
sort($updated_opts);
// for case insensitive sort use second argument
// sort($updated_opts, SORT_STRING | SORT_FLAG_CASE);
var_dump($updated_opts);