I'm trying to remove everything from a string but just numbers (0-9).
I thought this would work..
echo preg_replace("[^0-9]","",'604-619-5135');
But it echos "604-619-5135". What am I missing???
4 Answers
Try this:
preg_replace('/[^0-9]/', '', '604-619-5135');
preg_replace uses PCREs which generally start and end with a /.
4 Comments
Qtax
The inner/double quoting doesn't have anything to do with PCRE tho. Apparently (in the days before
(?flags)) the people who designed/wrote the function/API thought it was a good idea to pass the regex flags with the double quoted /flags form instead of using an extra function parameter.
Chris Eberle
@Qtax: good point, yeah I know that's where we get the word "grep" from ("g/re/p")
Jenuel Ganawed
adding character at the las part seems doesnt remove the part
Mr. Jo
Or just do it simple and use
/\D/ to get the number or /\d/ to get the string.This is for future developers, you can also try this. Simple too
echo preg_replace('/\D/', '', '604-619-5135');
4 Comments
Eoin
I have come back 2 the future and I can confirm they have still not found a better way.
mickmackusa
@Eoin to make this pattern "better" add a one-or-more quantifier (
+) after the D. This allows the regex engine to make longer and therefore fewer replacements. Imagine standing in front of a carton of eggs. If I asked you to pick up the dozen eggs, would you do 12 squats or just 1? Though I like to work out, I'd squat once and pick up all of the eggs as a matter of directness.
Jose Manuel Abarca Rodríguez
@mickmackusa, would you add another comment with such code, please 🙏?
mickmackusa
@Jos
echo preg_replace('/\D+/', '', '604-619-5135');You would need to enclose the pattern in a delimiter - typically a slash (/) is used. Try this:
echo preg_replace("/[^0-9]/","",'604-619-5135');
NOTE: if you are filtering strings containing - sign is not applicable to this answer because - stands for minus sign and is NOT filtered and removed. (like -2, -4 etc). If you still want to use it please remove - characters and then try.
(- + . e) characters are not stripped with this function
a much more practical way for those who do not want to use regex:
$data = filter_var($data, FILTER_SANITIZE_NUMBER_INT);
note: it works with phone numbers too.
5 Comments
Qrzysio
FILTER_SANITIZE_NUMBER_INT leaves plus + and minus - signs, not only digits.
Alp Altunel
yes I said it works with phone numbers like +905360000000 leaves out all other characters
Alexander Dobernig
This is e.g. a problem if you try to use it with Whatsapp as WA DOES NOT allow + signs!
mickmackusa
This answer is completely ineffective for the question asked. Proof: 3v4l.org/IMQeJ
Alp Altunel
if you read manual page for this you can see that your proof contains - character which is allowed for int if you use -2 for example. so you cannot apply this. you can use $str = str_replace("-", "", $str); and apply this filter_var.
echo preg_replace("[^0-9]", "this", '0-9 is replaced');outputs:this is replaced