Want to remove multiple commas [with or without spaces] with a single one. Tried this regex however it failed preg_replace("/\s{1,5},\s{1,5} /", ", ", $string);
Tried other solutions but can't find any solution where space also exists with comma.

Sample input

GUWAHATI, TEZPUR, , BAMUNI HILLS, MAHABHAIRAB TEMPLE, AGNIGARH ,   
GUWAHATI, TEZPUR ,   , BAMUNI HILLS,, MAHABHAIRAB TEMPLE, AGNIGARH,  
GUWAHATI, , TEZPUR, , BAMUNI HILLS, MAHABHAIRAB TEMPLE, AGNIGARH 

Expected output

GUWAHATI, TEZPUR, BAMUNI HILLS, MAHABHAIRAB TEMPLE, AGNIGARH

CodePudding user response：

You may use this solution:

$s = preg_replace('/^[,\h] |\h*(,)(?:\h*,) \h*|[,\h] $/m', '$1 ', $s);

RegEx Demo

Breakdown:

• ^[,\h] : Match 1 of comma or spaces after start
• |: OR
• \h*(,)(?:\h*,) \h*: Match 2 or more of comma optionally separated by spaces. Note that we match a single comma in capture group
• |: OR
• [,\h] $: Match 1 of comma or spaces before end
• '$1 ': Is replacement to put captured value of comma followed by a single space

CodePudding user response：

You can trim the $string from whitespace and commas using trim($string, ', \n\r\t\v\x00') (the chars are the default trim chars a comma) and then use preg_replace('/\s*(?:,\s*) /', ', ', ...):

<?php

$string = ", , GUWAHATI, TEZPUR, , BAMUNI HILLS, MAHABHAIRAB TEMPLE, AGNIGARH ,   ";
echo preg_replace('/\s*(?:,\s*) /', ', ', trim($string, ", \n\r\t\v\x00"));
// => GUWAHATI, TEZPUR, BAMUNI HILLS, MAHABHAIRAB TEMPLE, AGNIGARH

See the PHP demo

The \s*(?:,\s*) pattern matches zero or more whitespace followed with one or more sequences of a comma and zero or more whitespaces. Here is the regex demo.