Remove specific characters at beginning and end of string

Question

I am using PHP and I am trying to remove all underscore characters from the end and beginning of a string.

Here's the string: ____a_b_c__________
And I want the result to be: a_b_c

I have tried with this regular expression but it's not working:

preg_replace('/[^a-z]+\Z/i', '', '____a_b_c__________');

ArtisticPhoenix · Answer 1 · 2018-04-09T00:19:53.030

5

Why not just use trim:

$string = trim($string, '_');

Regex is for pattern matching ___ is not a pattern it's just underlines.

But if I was gonna use a Regex, I'd do something like this:

$string = preg_replace('/^_+|_+$/', '', $string);

For the regular expression

Then we just replace it with ''

edited Apr 09 '18 at 00:19

answered Apr 09 '18 at 00:12

ArtisticPhoenix

1

Ha! I cant believe it was that easy. Thanks. – LargeTuna Apr 09 '18 at 00:14
everything is easy for me, well almost everything. – ArtisticPhoenix Apr 09 '18 at 00:16
How about this one: how would I remove all duplicate and triplicate ___ underscores from a string. Sometime there may even be 5 - 10 underscores, i just want it to be one underscore. – LargeTuna Apr 09 '18 at 01:34
`$string = preg_replace('/_{2,}/', '_', $string);` or `'/_+/'` or `$string = preg_replace(['/^_+|_+$/','/_{2,}/'],['', '_'], $string);` – ArtisticPhoenix Apr 09 '18 at 01:37

1 Answers1