how to get convert comma separated string to arrray php code example

Example 1: array to string separated by comma php

$arr = array ( 0 => "lorem", 1 => "ipsum", 2 => "dolor");

$str = implode (", ", $arr);

Example 2: php change array into comma delimited string

$tags = implode(', ', array('tag1','tag2','tag3','tag4'));