This should be obvious, but I'm having trouble.
I want to replace several characters (dashes, spaces, underscores) with an empty string, but I've got something wrong.
This code: $tmp = preg_replace('/[ -_]/', '', 'filename-1055');
...returns this: "filename"
...when I'm expecting this: "filename1055"
Why the truncation?
Try str_replace instead:
$tmp = str_replace(array("-", "_", " "), "", 'filename-1055');
Unless there is a particular reason you are using preg_replace.
str_replace(array("-", "_", " "), "", $string); would meet OPs requirements better. "I want to replace several characters (dashes, spaces, underscores) with an empty string"str_replace is much less overhead for a simple task than preg_replace. +1.In a character class, dash - is the range operator, so your class [ -_] means any character in the range (space) to _.
You have two possibilities:
1- move the dash in the first or last position in the character class: [- _] or [ _-]
2- or escape it: [ \-_]
Try this way, DEMO
$re = "/([-\\s_])/";
$str = "filename-1055\n";
$subst = "";
$result = preg_replace($re, $subst, $str, 1);
Its because you did not escape - (range operator inside []) with \-. Correct code would be:
$tmp = preg_replace('/[ \-_]/', '', 'filename-1055');
