javascript - Removing duplicates in a comma-separated list with a regex? -

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i'm trying figure out how filter out duplicates in string regular expression, string comma separated. i'd in javascript, i'm getting caught how use back-references.

for example:

1,1,1,2,2,3,3,3,3,4,4,4,5

becomes:

1,2,3,4,5

or:

a,b,b,said,said, t, u, ugly, ugly

becomes

a,b,said,t,u,ugly

why use regex when can in javascript code? here sample code (messy though):

var input = 'a,b,b,said,said, t, u, ugly, ugly'; var splitted = input.split(','); var collector = {}; (i = 0; < splitted.length; i++) {    key = splitted[i].replace(/^\s*/, "").replace(/\s*$/, "");    collector[key] = true; } var out = []; (var key in collector) {    out.push(key); } var output = out.join(','); // output 'a,b,said,t,u,ugly'

p/s: 1 regex in for-loop trim tokens, not make them unique


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