How can I explode and trim whitespace?

Question

For example, I would like to create an array from the elements in this string:

$str = 'red,     green,     blue ,orange';

I know you can explode and loop through them and trim:

$arr = explode(',', $str);
foreach ($arr as $value) {
    $new_arr[] = trim($value);
}

But I feel like there's a one line approach that can handle this. Any ideas?

Answer 1

You can do the following using array_map:

$new_arr = array_map('trim', explode(',', $str));

Answer 2

An improved answer

preg_split ('/(\s*,*\s*)*,+(\s*,*\s*)*/', 'red,     green thing ,,
              ,,   blue ,orange');

Result:

Array
(
    [0] => red
    [1] => green thing
    [2] => blue
    [3] => orange
)

This:

• Splits on commas only
• Trims white spaces from each item.
• Ignores empty items
• Does not split an item with internal spaces like "green thing"

Answer 3

The following also takes care of white-spaces at start/end of the input string:

$new_arr = preg_split('/\s*,\s*/', trim($str));

and this is a minimal test with white-spaces in every sensible position:

$str = ' first , second , third , fourth, fifth ';
$new_arr = preg_split('/\s*,\s*/', trim($str));
var_export($str);

Answer 4

this how you replace and explode in a single line of code

$str = 'red,     green,     blue ,orange';

$new_string = explode(',',preg_replace('/\s+/', '', $str));

will output the results as

Array
(
    [0] => red
    [1] => green
    [2] => blue
    [3] => orange
)

Answer 5

By combining some of the principals in the existing answers I came up with

preg_split ('/\s*,+\s*/', 'red,     green thing ,,  ,,   blue ,orange', NULL, PREG_SPLIT_NO_EMPTY);

The reasoning behind it is that I found a bug in this answer, where if there is a comma at the end of the string it'll return a blank element in the array. i.e.

preg_split ('/(\s*,*\s*)*,+(\s*,*\s*)*/', 'red,     green thing ,,  ,,   blue ,orange,');

Results in

Array
(
  [0] => red
  [1] => green thing
  [2] => blue
  [3] => orange
  [4] => ''
)

You can fix this by using PREG_SPLIT_NO_EMPTY as mentioned in this answer to remove it, but once you are doing that there is technically no need to remove consecutive commas via the regex, thus the shortened expression

Answer 6

You can also do this with a one line regex

preg_split('@(?:\s*,\s*|^\s*|\s*$)@', $str, NULL, PREG_SPLIT_NO_EMPTY);

Answer 7

try this:

$str = preg_replace("/\s*,\s*/", ",", 'red,     green,     blue ,orange');

Answer 8

SPECIFICALLY for the OP's sample string, because each substring to be matched is a single word, you can use str_word_count().

Code: (Demo)

$str = ' red,     green,     blue ,orange ';
var_export(str_word_count($str,1));  // 1 means return all words in an indexed array

Output:

array (
  0 => 'red',
  1 => 'green',
  2 => 'blue',
  3 => 'orange',
)

This can also be adapted for substrings beyond letters (and some hyphens and apostrophes -- if you read the fine print) by adding the necessary characters to the character mask / 3rd parameter.

Code: (Demo)

$str = " , Number1 ,     234,     0 ,4heaven's-sake  ,  ";
var_export(str_word_count($str,1,'0..9'));

Output:

array (
  0 => 'Number1',
  1 => '234',
  2 => '0',
  3 => '4heaven\'s-sake',
)

---

Again, I am treating this question very narrowly because of the sample string, but this will provide the same desired output:

Code: (Demo)

$str = ' red,     green,     blue ,orange ';
var_export(preg_match_all('/[^, ]+/',$str,$out)?$out[0]:'fail');