php preg_split or explode. Not removing the character

Question

I have been trying several ways to solve my issue and have found a poor work-around, but I would like to know if there is something else out there. I have a string of several sub-strings which are separated by commas. I can split this up into an array using preg_split or explode. BUT some of the sub-strings also contain commas that I do not want to split into separate array members. My work around is to include a full stop at the end of every string and then tell explode to split only on ".,". Example string:

$string = "Henry the horse, Billy the donkey, Harry the mule, George, the hippo";

Work-around

$string = "Henry the horse., Billy the donkey., Harry the mule., George, the hippo.";
$list = explode('.,',$string);

I can't for the life of me think of any way to tell the program that the comma after George is not the end of the sub-string. Another (related) issue is that I would like to split the string at the commas BUT include the commas in the array members.

==> Henry the horse,
==> Billy the donkey,
==> Harry the mule,
==> George, the hippo,

My idea for this is simply to add them again after. Is there a simpler way? In other words is there a way of splitting at a delimiter BUT keeping the delimiter in the array members?

If you don't know the logic on how to decide whether a comma is part of the substring or a delimiter, then it will be impossible to tell PHP to do it. So what is the logic? — trincot, Nov 25 '18 at 09:58

score 1 · Answer 1 · answered Nov 25 '18 at 10:05

1

I'm guessing that each substring must start with a capital. Then this would do it:

$string = "Henry the horse, Billy the donkey, Harry the mule, George, the hippo";

preg_match_all("~[A-Z].*?(?:$|,)(?!\s*[a-z])~", $string, $result);

$result[0] will contain the following output:

[
    "Henry the horse,"
    "Billy the donkey,"
    "Harry the mule,"
    "George, the hippo"
]

answered Nov 25 '18 at 10:05

trincot

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Yes, the string originates from an array in which each member starts with a capital letter, so this should do the trick. I didn't know that preg_match_all returned an array! I am going to have to get my head around the regex (tutorial time). Thanks. – charco Nov 26 '18 at 15:49

score 0 · Answer 2 · answered Nov 25 '18 at 09:49

0

You could use lookarounds or (*SKIP)(*FAIL). Either usw ,(?! the) or , the(*SKIP)(*FAIL)|, with preg_split().

Tapping on my mobile

answered Nov 25 '18 at 09:49

Jan

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score 0 · Answer 3 · answered Feb 23 '23 at 11:01

preg_split supports the flag PREG_SPLIT_DELIM_CAPTURE. See the documentation.

The delimiter needs to be in parentheses:

php > var_dump(preg_split('/(, )/', 'Henry the horse, Billy the donkey,
Harry the mule, George, the hippo', -1, PREG_SPLIT_DELIM_CAPTURE));

array(9) {
  [0]=>
  string(15) "Henry the horse"
  [1]=>
  string(2) ", "
  [2]=>
  string(16) "Billy the donkey"
  [3]=>
  string(2) ", "
  [4]=>
  string(14) "Harry the mule"
  [5]=>
  string(2) ", "
  [6]=>
  string(6) "George"
  [7]=>
  string(2) ", "
  [8]=>
  string(9) "the hippo"
}

php preg_split or explode. Not removing the character

3 Answers3