[thelist] Re: Regex remove repeats
Burhan Khalid
thelist at meidomus.com
Thu Jan 27 01:55:10 CST 2005
Chris Nicholls wrote:
> >>I'm stuck on writing a regex that is going to lok ahead to see if the
> >>next item in the comma separated list is the same as the last and, if
> >>it is, to remove it
>
> This isn't a regex, but one solution, simpler and more scalable,
> depending on your scripting language, would be:
>
> 1. Split string into list
> 2. Create an empty "holding" array. Also create an empty hash/struct
> 3. Loop through list see if value exists as a key in your new struct.
> If not, add value to holding array, and set flag in struct saying
> value has been "seen"
> 4. Write holding array, which now contains only unique values, back out
> to new list.
>
> In Perl:
[ trimmed ]
I'm not sure I understood the entire step 3, but to me it seems like you
need to find uniques in a set of items that are originally in the format
"a,b,c,3,df,er". The following is a PHP solution to the problem (as I
understand it).
In PHP :
<?php
//Step 1
$contents = explode(",",$string);
//Steps 2 & 3
$unique_array = array_unique($contents);
//Step 4
$unique_list = implode(",",$unique);
?>
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