PHP regex to remove multiple ?-marks

Question

I'm having trouble coming up with the correct regex string to remove a sequence of multiple ? characters. I want to replace more than one sequential ? with a single ?, but which characters to escape...is escaping me.

Example input:

Is this thing on??? or what???

Desired output:

Is this thing on? or what?

I'm using preg_replace() in PHP.

Answer 1

preg_replace('{\?+}', '?', 'Is this thing on??? or what???');

That is, you only have to escape the question mark, the plus in "\?+" means that we're replacing every instance with one or more characters, though I suspect "\?{2,}" might be even better and more efficient (replacing every instance with two or more question mark characters.

Answer 2

preg_replace( '{\\?+}', '?', $text );

should do it.

You need to escape the question mark itself with a backslash, and then escape the backslash itself with another backslash.

It's situations like this where C#'s verbatim strings are nice.

Answer 3

This should work (I have tested it):

preg_replace('/\?+/', '?', $subject);

Answer 4

preg_replace('/\?{2,}/','?',$text)

Answer 5

this should do it

preg_replace('/(\?+)/m', '?', 'what is going in here????');

the question mark needs to be escaped and the m is for multiline mode.

This was a good web site to try it out at http://regex.larsolavtorvik.com/

Answer 6

Geez, five different regexes and they all seem to work. I hate when there's so many different ways to do something :)

Answer 7

have you tried the pattern

[\?]+

with the replacement of "?"

Answer 8

str_replace('??', '?', 'Replace ??? in this text');