how do i remove a comma off the end of a string?

Question

I want to remove the comma off the end of a string. As it is now i am using

$string = substr($string,0,-1);

but that only removes the last

Answer 1

A simple regular expression would work

$string = preg_replace("/,$/", "", $string)

Answer 2

Precede that with:

if(substr($string, -1)==",")

Answer 3

$string = rtrim($string, ',');

Docs for rtrim here

Answer 4

i guess you're concatenating something in the loop, like

foreach($a as $b)
  $string .= $b . ',';

much better is to collect items in an array and then join it with a delimiter you need

foreach($a as $b)
  $result[] = $b;

$result = implode(',', $result);

this solves trailing and double delimiter problems that usually occur with concatenation